The election of Donald Trump, and the early days of his presidency, have driven many Americans to rummage through history in search of context and understanding. Trump himself has been compared to historical figures ranging from Ronald Reagan to Henry Ford, and from Andrew Jackson to Benito Mussolini. His steps have been condemned as unprecedented by his critics, and praised as historic by his supporters.

To place contemporary events in perspective, we turned to a pair of historians of the United States. Julian Zelizer is a professor of history and public affairs at Princeton University. He is the author, most recently, of The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society. Morton Keller is a professor emeritus of history at Brandeis University. He has written or edited more than 15 books, including Obama’s Time: A History. They’ll be exchanging views periodically on how to understand Trump, his presidency, and this moment in political time. —Yoni Appelbaum

Morton Keller: Within the space of a couple of weeks, President Donald Trump and House Speaker Paul Ryan suffered the major setback of a failure to get the House to pass their Obamacare reform bill, and Senate Minority Leader Charles Schumer and the Democrats suffered the major setback of a failure to block the appointment of Neil Gorsuch to the Supreme Court.

A clutch of questions emerges from these developments. Is Obamacare saved? If it will be amended, how and by how much? Or will the Republican repeal-and-replace goal come back to life?

Will Trump have another Supreme Court appointment (or two) to make before the end of his first term? Will the filibuster have a rebirth when (or if) the GOP-led Congress begins to pass substantive legislation? Or is it destined to join the Dodo in the land of species made obsolete by change?

One thing seems clear: what is happening in Washington now is not solely the unsettling presence of Trump. Surely Trump's—shall we say unusual—personality and mode of governance is an important factor. But the fact that he and his quirks reside in the White House is in itself the most conspicuous result of a sea change in the character of American political culture.

The rejection of Robert Bork in 1981 and the assault on Clarence Thomas in 1991 were forecasts of what was to come. But the strongly conservative Antonin Scalia was confirmed 98-0 by the Senate in 1986, and the strongly liberal Ruth Bader Ginsberg by 96-3 in 1993.

In my view, the confrontational die was cast by the contested 2000 presidential election. Democrats were deeply angered by what they regarded as a Supreme Court-contrived result. That anger got a new lease on life in 2016, with  Democrats dwelling on the uncertain influence of the Russians rather than the much more probable lapses of the Clinton campaign in a contest which could quite readily have gone the other way.

But whatever the causes, here we are—and what if anything can be done about it? My view is that as the First Hundred Days milestone of the Trump administration approaches, it would serve both sides well if they took a deep breath and considered the long-term costs as well as the short-term benefits of paying excessive attention to their core support. I don't think that Trump will flourish politically if he tries to rely on his true believers. And I don't think the high road to Democratic recovery is defined by the take-no-prisoners Trump haters. The Whigs learned the lesson of learning from and not just demonizing the opposition in the 1830s. The same lesson was ignored by the Secessionists in the 1860s and by the anti-FDR Republicans in the 1930s and 1940s.   

Beyond the deprived Deplorables of the Midwest and the ideologues of the House Republican Freedom Caucus, or the take-no-prisoners left liberals of New York, California, and the college towns, there is a larger, conflicted, concerned plurality hungry for a politics and government that is less polarized and more effective. The party that is first to figure out how to appeal to the muddled middle without alienating its convinced core is the party that is most likely to flourish in the future.

Some possible straws in the wind: Trump's removal of Stephen Bannon from the National Security Council, or the tempered response of the Democratic leadership to the US missile assault on the Syrian airfield from which Bashar al-Assad's planes launched their latest gas attack.

Julian Zelizer: Partisanship has taken its toll on Washington. While this is not the first period in American politics where partisan polarization divided the nation—think of the late 19th century, for instance—this is one of the worse periods. There is just very little common ground on Capitol Hill. I agree that Trump is a product and not a cause of bitter polarization. As the gridlocked nomination of Merrick Garland reminds us, politics was pretty bad before Trump took center stage.

I don't think there are many straws in the wind though. Partisanship is not a product of bad feelings or had people but of institutions and political structures, as well as demographic changes, that push our leaders apart. All of those remain firmly in place.

The only way we really make progress is to reform the way that politics works. Without changes to our districting process the Freedom Caucus will remain in place. Without campaign finance changes politicians will still be turning to issue based interest groups who will pressure politicians to stick to the party line. We would also need changes in non-government institutions such as media outlets to obtain less partisan news. Those changes can't be legislated but will have to be a product of the producers and editors who make the news.

Until the nation does the partisan pressures will only intensify and it's hard to see the light that would move the leaders of the parties to change directions. Trump might certainly be an outlier in his behavior and more uncontrollable than anyone else in the White House but he reflects the way partisan polarization has reshaped the fundamentals. Perhaps the reason that the Gorsuch nomination process was so hard to watch was because it simply exposed our current state of politics.

Keller: I don't fully agree. While political events like the 2000 and 2016 elections exacerbated the gridlock of the political process, the fact remains that politicians tend not to be so much ideologues as rent-seekers who, yes, do what they believe in but are also, when it suits them, able to function across party lines and get things done. (Take, for example, Clinton's reset on Serbia-Kosovo in the 1990s, his welfare bill, or Bush and Kennedy and No Child Left Behind.)

You are quite right to emphasize the current intensity of political polarization. But that has happened before: e.g., the slavery-secession division of the 1850s (a discouraging example), and the anti-FDR/anti-New Deal furor of the mid-1930s (a more hopeful example). The ferocity of the anti-Roosevelt rhetoric easily matches that currently directed at Trump.

If Trump should adopt a more tempered approach to his presidency (increasingly a political necessity, though there's no telling with him), there won't be an explosion of political good feeling. But there may be a chance of something closer to the customary American political ambience of highly contentious but mutually beneficial wheeling and dealing.

What to do about Assad and Syria, or what to do about taxes and infrastructure, doesn't have the ideological or cultural heft of the issues that dominated the early months of the Trump presidency: Did Trump and the Russians collude to defeat Clinton? Did Obama use the intelligence establishment to spy on the Trump campaign? Should Obamacare be replaced? Should the Republicans be prevented from nominating a Supreme Court justice?

Zelizer: While it is true that there are degrees of partisanship and moments of breakthrough in our current era, they are far and few between. The No Child Left Behind example is instructive. President Bush and Senator Ted Kennedy worked together on the legislation following the contentious 2000 election, but then “bipartisanship” almost totally broke down, including over national-security issues post-9/11. The same was true with the Serbia-Kosovo examples. Sure, there has been issue-based bipartisanship, but the general atmosphere of the 1990s brought us the impeachment. During the 1930s, the anti-Roosevelt sentiment was very intense, but of course in that period the two parties were deeply divided so there were more structural opportunities for bipartisan cooperation.

Of course, Trump does have the opportunity to try to break through this. It will be difficult. His victory in 2016 depended on partisan polarization. Most Republicans in red states voted for him despite all the discussion of a intra-party “civil war.” This was more important than the small number of swing voters in states like Michigan and Wisconsin who moved from the Democratic camp to the Republican. If Trump tried to makes some bipartisan deals in the next few months he will encounter fierce resistance from Freedom Caucus Republicans as well as most of the others in the GOP, who, despite all the rhetoric, still face the same electoral incentives not to cooperate with Democrats. Most Democrats would also have trouble at the electoral level if they decided to work with this president.

All of this is to say that I’m skeptical any president—especially someone as contentious and divisive as Trump—can change the partisan dynamics that we are seeing. Without changing the institutions and the processes, any bipartisan moments will be an aberration.