Erin Scott / Reuters

Rambunctious freshmen come into the House in a wave election, shake things up, challenge the leaders, divide the party. That is a pretty good capsule description of “the squad,” the four freshman congresswomen whose squabble with Speaker Nancy Pelosi has now been overshadowed by the astonishingly racist attacks on them by the president of the United States, and by the defense of those attacks by nearly all congressional Republicans. For now, the tensions between the squad and the leaders has been submerged, as Democrats, starting with the speaker, have come to their defense and closed ranks to condemn Trump’s racist and ignorant remarks. But the tensions over tactics, strategies, and outcomes are still there, and will inevitably reemerge.

In some respects, there is nothing new about tensions between freshman members of the House and its leadership. The wave classes of 1958, 1964, and 1974 for the Democrats, and 1994 and 2010 for the Republicans, brought similar struggles. Looking closely at them helps reveal both what they share with today’s tensions and what’s genuinely distinctive about this moment.

Democrats gained 48 seats in 1958, the second midterm election of Dwight Eisenhower’s presidency, including seats won by a substantial number of non-southern liberals that added to their large majority in the House. The 63 freshmen included a number of notables who played a big role in the House in subsequent decades—including Bob Giaimo of Connecticut, John Brademas of Indiana, Dan Rostenkowski of Illinois, Jim O’Hara of Michigan, Ken Hechler of West Virginia, and Bob Kastenmeier of Wisconsin. But in many ways, the biggest influence came from a House member who left for the Senate that year, Minnesota’s Eugene McCarthy.

McCarthy was a liberal agitator who had bristled at the continuing oversize role of southern conservative Democrats, known then as Boll Weevils, after the insect that infects cotton. He organized a group of like-minded members into McCarthy’s Marauders, including George McGovern, Stewart Udall, Frank Thompson, and Lee Metcalf, all of whom went on to long and significant political careers. They held a weekly Friday luncheon to plot strategy. McCarthy focused liberals on trying to capture influence commensurate with their numbers; after the new class of ’58 came in, they masterminded the creation the next year of the Democratic Study Group, which had an outsize influence on the House. The DSG crafted the major reforms of the early 1970s that were implemented with the votes of the huge freshman class of 1974—reforms that persisted until Newt Gingrich, in one of his first acts as speaker in 1995, found a way to kill them.

The Democratic Study Group became the strategic base for House liberals, but also had a broader reach. Powerful committee chairs used their near-monopoly on information to maintain control over votes in committee and on the floor. The new group became a major information outlet on legislation, challenging that monopoly. Speaker Sam Rayburn was a master at balancing power centers in the House, and was not thrilled at the audacity of these junior members, although they gave him no public or frontal challenge. But Rayburn was also not happy with the arrogance of right-wing committee chairs such as Howard “Judge” Smith, who used the House Rules Committee to kill any bills he did not like—and did not limit his antipathy to civil-rights legislation. So Rayburn used the impetus of the new members to thwart Smith and open up opportunities for liberal legislation. That enabled passage of much of the progressive Kennedy program, and the Great Society that followed in 1965–66.

That program, including landmark civil-rights and voting-rights bills, federal education reform, Medicare, and Medicaid, among others, was facilitated by the arrival of 71 Democratic freshmen in the 1964 elections. The net gain of 36 seats gave Democrats a two-thirds majority. Significantly, despite these gains, Democrats lost a number of once-safe seats in the South to Republicans for the first time since Reconstruction, heralding the coming regional realignment and the weakening power of the Boll Weevils. The new freshman class brought a number of important liberal members to Washington, including John Tunney, Sid Yates, Lee Hamilton, Andy Jacobs, John Culver, John Conyers, Bill Ford, John Gilligan, and Tom Foley. They bristled at the efforts of committee chairs to limit their role, and experienced tension with Speaker John McCormack, who was not a strong leader and did not champion their desire for a larger impact. But given that there was a president elected in a landslide who promoted their substantive agenda, their main role was to provide the votes for the bills that Lyndon Johnson backed.

Like the class of 1958, the 75 members of the class of 1974 came in with the second midterm of an incumbent Republican—in this case, President Richard Nixon. Their landslide at a time of scandal brought them a nickname: “Watergate Babies.” Some of the members of that class stayed in the House for decades, amassing power—George Miller, Norm Mineta, Henry Waxman, Steve Solarz, Phil Sharp, and Tom Downey among them. Others, such as Chris Dodd, Tom Harkin, Paul Simon, Paul Tsongas, and Max Baucus, moved to the Senate and had illustrious careers. (Jim Blanchard did the same as governor of Michigan and ambassador to Canada.)

As the historian John Lawrence recounted in his excellent book The Class of ’74, the freshmen were eager to upend the power structure and disdainful of many of the committee chairs. They helped propel three of those chairs with seniority out of office, upending the seniority system, while also providing votes for more extensive reform that spread power and resources to junior members and to subcommittees.

But the reforms that were implemented had actually been initiated, and received their first successes, before that class arrived. They were spearheaded, through the DSG, by people such as Jim O’Hara, Bob Kastenmeier, Ben Rosenthal, and Don Fraser, who had come either in the class of 1958 or in the two elections that followed. So the resonant impact of dramatic change in the House that occurred after the class of 1974 arrived was actually grounded in the actions of members elected in 1958 and 1962 who had not lost their revolutionary zeal, and who had enough experience to know how to write reforms and get them implemented as soon as they had reinforcements.

The 1974 class was not discouraged or reined in by Speaker Carl Albert, but his soft-spoken and more reticent style clashed with theirs; indeed, before their first year in Congress was done, some of the class tried to get him ousted as speaker to be replaced by Majority Leader Tip O’Neill (who was appalled by the attempt). Most of the class rallied around Albert, and the tension dissipated. The liberal agitators who had prolonged careers in Congress stayed liberal, but largely became pragmatic problem-solving lawmakers—like Waxman, working with the Reagan administration to expand Medicaid and protect Medicare, or Miller, who worked with the George W. Bush administration to create No Child Left Behind.

In some respects, the Republican class of 1994 resembled the Watergate Babies—a large class of revolution-minded freshmen, 73 in all, making up nearly a third of the Republicans in the House, while giving the party its first majority in 40 years. Contrary to conventional wisdom, they were not all bomb-throwers—the class included moderates such as Tom Davis of Virginia and Ray LaHood of Illinois, both of whom became important forces in the House when there were still pragmatic Republicans. But the majority of the new class had been either recruited by Gingrich or tutored by him in approach and language, or both. They were the culmination of Gingrich’s 16-year battle to tribalize and nationalize congressional politics, until voters were so disgusted with Washington that they would throw the incumbent party out.

Most of his recruits and trainees won—including such right-wing stalwarts as Bob Barr, Sam Brownback, Helen Chenoweth, Tom Coburn, Lindsey Graham, J. D. Hayworth, Mark Sanford, John Shadegg, and Steve Stockman. Some in the class, such as Graham, Coburn, Saxby Chambliss, and Rob Portman, moved on to the Senate—where, as Sean Theriault pointed out in his book The Gingrich Senators, they and compatriots such as Rick Santorum (class of ’92) brought Gingrich’s tribalism and disdain for norms to that body. A few, including Barr and Graham, were the shock troops who pushed for Bill Clinton’s impeachment and argued for it at the trial in the Senate.

The Gingrich class of ’94 made him speaker, and he used their numbers and revolutionary zeal to consolidate power in the speakership, ram through many elements of their Contract with America, and pass other conservative bills, most of which died in the Senate, where the Republican Bob Dole was the majority leader. Gingrich complained that he could do more business with President Clinton than with his own party counterpart, and ended up calling Dole “the tax collector for the welfare state.”

But Gingrich was also bedeviled by his progeny, who were deeper true believers in the evil of government than he was, and who chafed at his imperious approach to running the House. While he succeeded in winning a second consecutive majority for his party in 1996, as Clinton simultaneously trounced Dole to win a second term, his inability to push forward his members’ vision of minimal government, his own ethics issues, and his failed interactions with Clinton doomed his speakership after only two terms. While just a small portion of the ’94 class is still in the House, its hard-line, uncompromising approach to governance laid the groundwork for the even more radical members of the next wave group, the class of 2010.

In 1974, we had the Watergate Babies; in 2010, we had the Tea Party class. The net Republican gain of 63 seats—the largest the GOP had seen since 1938—actually included 87 new Republican House members, more than a third of their total of 242. The class was characterized by its hard-edged, right-wing populism, its distaste for President Barack Obama, and disdain for the usual ways of doing business. Notable members of the class included Mo Brooks, Paul Gosar, Raúl Labrador, Tim Huelskamp, Mick Mulvaney, Tim Walberg, Justin Amash, and Blake Farenthold. Early on, they had to deal with the debt limit. Two weeks after the election, the new Republican speaker, John Boehner, said of his freshmen and the debt ceiling, “I’ve made it pretty clear to them that as we get into next year, it’s pretty clear that Congress is going to have to deal with it … We’re going to have to deal with it as adults. Whether we like it or not, the federal government has obligations, and we have obligations on our part.”

His majority leader, Eric Cantor, did not take that message well, nor did the freshmen. Cantor made it clear that he would push for a confrontation, making demands of President Obama for drastic cuts in domestic spending, with the threat of breaching the debt ceiling if the demands were not met. Cantor wanted to use spending bills as another set of prongs in a frontal assault on Obama and the Democrats, and he had eager participants in that huge freshman class. Boehner’s attempts to keep his caucus together with a more “adult” approach were not helped when Paul Ryan—who, with Cantor and Kevin McCarthy, had labeled themselves the “Young Guns”—offered a budget, as chair of the Budget Committee, that failed to meet any of the promises that had been made to the Tea Party freshmen for dramatic budget cuts.

In the end, despite coming close to the brink, a debt-ceiling breach, with the ensuing consequences for the full faith and credit of the United States, was narrowly averted, but any significant resolution of the debt issue was scuttled by the right’s insistence on no new revenues to accompany budget cuts. In the aftermath, the second-term firebrand Jason Chaffetz, a role model for the freshmen, spoke for them and told journalists, “We weren’t kidding around. We would have taken it down.”

The debt-ceiling brouhaha was emblematic of the ongoing clash between Boehner, who wanted pragmatism to dominate the actions of the House, and radicals, including the core of the class of 2010, who wanted no deals and no moderation. After the next big midterm gain, in 2014, the radicals formed the Freedom Caucus, a striking move, since there was already a right-wing caucus, the Republican Study Committee, that included the vast majority of Republicans in the House. But believing the right-wing caucus was not right-wing enough, a group led by Mick Mulvaney, Jim Jordan, and Mark Meadows created the new caucus; of the nine founding members, three were from that 2010 class (Mulvaney, Raúl Labrador, and Justin Amash).

Not long after, besieged from his right, John Boehner, who had come into the House as a Gingrich-aligned firebrand himself, resigned. His replacement, “Young Gun” Paul Ryan, did not fare dramatically better, and resigned himself after less than four years in the job, at age 49. When Politico’s Tim Alberta, the author of the new book American Carnage, interviewed Boehner after his departure and asked about some of the Freedom Caucus stalwarts, he used terms such as idiots, anarchists, and assholes.

Now comes the Democratic class of 2018, 60 new Democrats from a net gain of 40 seats. The most striking thing about the class, as many have noted, is its remarkable diversity: More than half are women, and 40 percent are Hispanic, Native American, or other people of color. By contrast, the huge Democratic Watergate class had two women and one lone African American. But the class also boasts ideological diversity, with a large number of the freshmen joining both the Progressive Caucus and the more center-left New Democratic Coalition (with some overlap, and several joining the more conservative Blue Dog Coalition). Watching them, and spending time with many of them, I have also been struck by their enormous talent—including from some with no previous political or governmental experience, such as Alexandria Ocasio-Cortez; others who have been in the military or in intelligence, such as Abigail Spanberger and Elissa Slotkin; some, such as Dean Phillips, with a business background; and the most experienced of all, former Health and Human Services Secretary Donna Shalala.

Given that the net gain of 40 seats came mainly from districts Donald Trump had won in 2016, or where he came relatively close to winning, the Democrats’ most vulnerable seats today are largely occupied by more pragmatic and moderate members. That itself makes the class of 2018 different from the others: In 1974, even though many of the gains came from districts Nixon had won in 1972, the Democrats who made up the class were generally far more liberal than their districts, and driven to change the status quo in Congress. The Republican classes of 1994 and 2010 included a few moderates, but mostly, whether the districts were ones previously held by Republicans or taken from Democrats in blue areas, the new members were far more conservative, and far more radical in their approaches to politics, than previous freshman groups.

There is a commonality, of course, in the dynamic generated by each of these classes that come to Congress in wave elections. There is no doubt that, like the challenges faced by Speakers Rayburn, McCormack, Albert, Gingrich, and Boehner, Pelosi has to deal with divisions in her caucus, and faces pressure to put aside pragmatism and respond to the more insistent base that has been elevated by the influx of new members.

But there are differences as well. The story, focused as it is on the squad versus the speaker, is about four remarkable, different, and outspoken freshmen out of 60. While they have allies in their desire to be more confrontational with the Trump administration, to move more radical legislation and to head straight to impeachment without passing Go, there is nowhere near the larger center of gravity for upending the status quo that we saw with the classes of ’74, ’94, or ’10. And that is true of the Democratic caucus at large.

Pelosi is intent on protecting those members who won in the wave but have to respond to constituents who are not naturally inclined to vote for Democrats. Keeping the House from getting too far out over its skis is a constant challenge for her. Of course, the difficulty is heightened by the breadth and reach of social media and the 24-hour news cycle; if we had had a small group like the squad in 1974, for example, with the other members of the class arrayed ideologically like this one, I do not think that group would have been the dominant story.

But the ability of an individual with some celebrity to reach a huge audience via Twitter, and to use the leverage of social media to amplify a message that includes criticism of leaders, makes the story bigger. It is made greater yet by two other realities: a Republican tribal media and leadership that reinforce the narrative in order to make the squad the face of the Democratic Party and to divert attention from the Trump scandals and malfeasance, and a media that loves the narrative that Democrats are in disarray because it wants to show that it is not biased and can criticize both sides.

The diversity of the Democratic coalition in Congress is not just ideological; accommodating the massive changes that have taken place requires a set of skills that previous speakers did not have to employ. House Democrats reflect the diversity of the country, while Republicans move even more to be a congressional party of middle-aged and older white Christian males, with barely trace elements of women or people of color. And Pelosi also has to deal with a bombastic and narcissistic president who has no ability to make legislative deals or find coalitions; a dominant White House chief of staff, Mick Mulvaney, who came from the radical class of 2010, helped found the Freedom Caucus, and has no interest in compromise; and a Senate counterpart, Mitch McConnell, who has shown little regard for the long-standing norms of governance.

No one is better equipped to deal with these challenges than Nancy Pelosi. But no one should envy her task.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.