President Lyndon Johnson has enjoyed a remarkable run in Hollywood. Next month, the most recent addition to the fictional canon will be Rob Reiner’s LBJ, a movie starring Woody Harrelson as the oversized Texan who dominated American political life like almost no one else in the 1960s. Reiner’s film revolves around Johnson’s transition from serving as a frustrated vice president to becoming the president in November 1963 following President John F. Kennedy’s assassination. The film culminates with the passage of the historic Civil Rights Act of 1964 that desegregated public accommodations in the South. Like many recent films on LBJ, Harrelson plays Johnson as crass and ugly, but also as a politician whose heart was in the right place on the key domestic issue of the time.

In certain respects, producers, directors, writers, and actors who tend to lean toward the left have treated their work of this president as part of a broader effort to rescue American liberalism from its worst mistakes, to capture the hope that existed with Johnson’s White House in 1964 and 1965 before it was overwhelmed by Vietnam.

The irony for anyone who had been alive in the tumultuous Age of Aquarius is how easy it has become for intelligent audiences to forget the issue that loomed largest in the dark days of 1968: Vietnam.

The effort to save Lyndon Johnson “the southern liberal” from Lyndon Johnson “the war monger” started back in the 1970s. Films have undertaken a heroic effort to remind audiences of the progressive vision that shaped LBJ when he finally reached the Oval Office. In the 1978 television film King, LBJ was played by Warren Kemmerling as a shrewd politician who helped guide Martin Luther King Jr. toward the kind of grass-roots activities that would pressure Congress into voting for civil-rights legislation. In Lee Daniels’s The Butler, Liev Shreiber memorably captures an LBJ who starts by sitting on a toilet barking out racial expletives at his advisers as he asked them to help him keep black protesters “off the street” and insultingly telling his African American butler to bring him prune juice to relieve his constipation, but evolves into a president visibly moved as he watched the violence unfold in Selma on television when the police beat activists protesting for voting rights. More recently, an HBO film based on the Tony Award-winning play, All the Way, showed LBJ (played by Bryan Cranson) to be a principled liberal Democrat who was genuinely committed to pushing a bold civil-rights agenda even while he worried about a very serious political backlash. Robert Schenkkan’s riveting story captures all of the legislative cunning and political capital that Johnson deployed to move the Civil Rights Act of 1964. Selma was more critical of Johnson, emphasizing the ways that the president was complicit in J. Edgar Hoover’s smear campaign against King. Even in Selma, though, Ava DuVernay shows Johnson’s sympathy to the civil-rights cause amidst his overwhelming political fears about the activists going too far and too fast.

Hollywood has also portrayed LBJ as a skillful politician who knew how to get things done. In the era of constant gridlock that followed the 1960s, this story possesses continued appeal. Johnson’s crass and blunt mannerisms have been used to dramatize how the president’s forceful personality enabled him to move legislation through Washington’s tortured political process. Few actors have replicated the buffoon-like character that Rip Torn portrayed in a television film about J. Edgar Hoover in 1978. Instead, much more common has been the kind of acting offered by Randy Quaid in the 1987 television docudrama LBJ: The Early Years, when he brought to life the savvy and hardball style that accounted for Johnson’s meteoric rise to power, from working as a secretary to a member of Congress in the 1930s to becoming president three decades later.

Most films looking at Vietnam—like Platoon, The Deer Hunter, Coming Home, Apocalypse Now, Born on the Fourth of July, and Full Metal Jacket—have focused on the war itself and the experiences of veterans. The movies that turn to Washington have tended to paint Johnson as a Shakespearean character, tragically pushed into bad decisions. In one of the handful of movies that deals primarily with Johnson’s foreign policy, HBO’s Path to War, viewers saw Michael Gambon’s Lyndon Johnson as a tortured leader deeply committed to domestic reform but pushed by an array of devious, hawkish advisers and military officials deeper into the jungles of Vietnam. “I’m going to nip this in the bud,” Johnson promises Martin Luther King Jr., unaware of the kind of quagmire that he was getting the nation into. “I want war like I want polio,” LBJ says to Jack Valenti. “Shooting and bombing, it goes against every bone in my body.” Viewers see a president who, as he is remembered in popular mythology, was out of his league when dealing with foreign policy and, as a result, agreed to disastrous mistakes. The real villain in the film is not Lyndon Johnson—he is tragic—but Secretary of Defense Robert McNamara, played by Alec Baldwin to resemble Dr. Evil. He keeps promising the president that eventually the U.S. will be able to get out. The film was much stronger with regards to LBJ than Thirteen Days, an otherwise powerful account of the Cuban Missile Crisis that relegates Johnson to a minor role, primarily for comic relief.

Younger viewers who have grown up with these films could easily forget the front-page stories when Johnson announced that he would not run for reelection in 1968. “Johnson’s War” was raging in Southeast Asia, with American soldiers being sent home every week in body bags. Americans all over the country had family members who were already in the war or others who could soon be drafted. They watched with bated breath as the president and his advisers updated the country about what was happening overseas. By the time he left office in January 1969, LBJ had become the epitome of a bad president. The left hated him for betraying them by abandoning their domestic causes and bringing the nation into a deadly, imperialistic war. Conservatives didn’t think much of LBJ either. They believed that his misguided domestic policies had made conditions worse for law-abiding Americans, while the president’s refusal to unleash all of the nation’s airpower on communist troops had resulted in ground forces being bogged down in the jungles of Vietnam. Mainstream liberal Democrats felt more sympathetic to LBJ’s policies, but concluded that he had undermined the standing of their party and created the opportunity for someone as odious as Richard Nixon to succeed. The 1960s, they said, were supposed to end with a burst of liberal progress but instead ended with an untrustworthy, communist-baiting, law-and-order Republican taking over the presidency. Johnson was to blame.

Historians have not been as kind to LBJ as Hollywood when assessing his impact on America’s role in the world. Foreign-policy historians have produced important work in recent years showing how Vietnam was neither an inevitable mistake nor a military operation pushed on an unknowing president by advisers. Rather, a cohort of outstanding scholars has used archival records, particularly the White House presidential recordings, to show that Johnson very much knew the risks he was taking by accelerating this war, and repeatedly ignored the warnings of multiple advisers and colleagues who told him that a war in Vietnam was unnecessary and unwinnable. The most important work on this subject, Fredrik Logevall’s Choosing War, brilliantly recounts how Johnson understood all of the risks associated with sending troops into this battle and heard repeatedly from southern hawks, liberal Democrats, and foreign leaders that a negotiated settlement would be better.

But as a result of both his machismo and his desperate efforts to prevent Republicans from attacking him as weak on defense, the same sort of baldly political calculation that brought him success on domestic policy, Johnson decided to escalate the American military presence in the deadly jungles of the region. Vietnam, according to Logevall, was the result of poor presidential decision making, mistaken calculations, and a commander in chief who fully understood the problems with this operation but moved forward anyway.

The time has come for a good film that captures this other side of LBJ: not the tragic leader but the culpable commander in chief, the president who sought to protect his political standing through disastrous decisions. Americans need to see a talented actor portray Johnson reading Vice President Hubert Humphrey’s famous 1965 memo, in which he wrote that “politically, it is always hard to cut losses. But the Johnson Administration is in a stronger position to do so than any Administration in this century. 1965 is the year of minimum political risk for the Johnson Administration. Indeed, it is the first year when we can face the Vietnam problem without being preoccupied with the political repercussions from the Republican right.” Cut to the next scene: Johnson kicks Humphrey out of his inner circle of advisers and only gives the hawks a seat at the table.

This Hollywood story of Lyndon Johnson’s failure is needed more urgently today than ever before. There is still a strong tendency to believe, against all odds, that the “political system” or the so-called “adults in the room” will somehow protect the United States from the worst instincts of a president when it comes to war and peace. Somehow, Americans say to themselves, democracy will survive dangerous presidential bluster, the emasculation of diplomacy, and constant militaristic threats.

That hope is misplaced. Ken Burns’s gripping PBS documentary on Vietnam shows how bad the situation can become. Schenkkan has written a sequel play to All the Way, entitled The Great Society, that puts more emphasis on the second half of LBJ’s administration. As Americans learned with Lyndon Johnson, a president with far more experience, gravitas, and political commitment than Donald Trump can lead the nation right into a devastating war.

Downplaying the ways in which Johnson was directly responsible for Vietnam risks underestimating the horrendous outcomes that can result from reckless presidential decisions.