I was 21 years old in 1968. Nixon-Humphrey was my first presidential election. I was the designated Jewish politico at Middlebury College—marched on Washington, levitated the Pentagon, told the Teach-In crowd “Hell no, we won’t go!” Didn’t go. I was very convinced. As a rock-and-roll devotee I figured the revolution would have a soundtrack and I would pick the cuts.

Richard Nixon was clearly not a man to be trusted. “The New Nixon” he was touting himself, but anyone who was paying attention could tell he was the same old Dick. The Vietnam War wasn’t going well—was, in fact, squandering tens of thousands of my generation’s lives—and I blamed President Lyndon Johnson for prosecuting it. Hubert Humphrey, his vice president, an old-line liberal, should have known better but was LBJ’s apologist. Humphrey was running against Nixon.

In my youth and absolutism, new to the real world of incremental gains and accommodation, I was among many who said, “The lesser of two evils is still an evil” and refused to vote for either of them. (In my wisdom I voted the Peace and Freedom Party line for Eldridge Cleaver.) The phrase popular at the time was “to make the contradictions manifest.” As if, when a man so obviously corrupt as Nixon was elected, the American people would immediately become aware of their terrible mistake and rise up en masse to replace one class of rulers with another. I wanted all of what I wanted and would be satisfied with nothing less.

Our numbers were significant. Never mind that as a senator from Minnesota, Humphrey was the lead author of the Civil Rights Act of 1964, was intimately involved in creating the Peace Corps and had chaired the Senate Select Committee on Disarmament—we simply could not in good conscience put into power a man who was so compromised.

And so we got two terms of Nixon—or actually a term and a half.

I know now that I abdicated and am personally responsible for the expansion of the Vietnam War, the bombing of Cambodia, Watergate, the enemies list, and the loss of respect for the institution of the presidency provided by Nixon’s near impeachment and then resignation. America was not the better for my vote.

I learned my lesson. In 2000 I told everyone who would listen that the major issue in the Bush-Gore race was the Supreme Court. There would be no surprises; if elected, George W. Bush would nominate Justices consistent in their conservatism who would determine the retrograde direction of the court for a generation. More than his right-wing policies, this wrong-headed judicial upheaval would be his legacy—if we allowed it. We had to vote for Gore. And yet there was a determined contingent of ideologues, particularly those in Florida, who voted for Ralph Nader.

And so we got two terms of Bush.

I am pleased to report that I am not to blame for the war in Iraq, the Citizens United decision that widened the opening of American politics for purchase, or the gutting of the Voting Rights Act—but Nader voters are.

Donald Trump is not a man to be trusted. His bigotry is undeniable; his instability paraded for all to see; he has displayed his disqualifications for office so often the eyes glaze over at their recitation. And yet we have “Bernie or Bust,” the folks threatening to sit out the election rather than vote for the candidate closest to their ideals—a petulant response to a political defeat. I am familiar with the politics of petulance, but I am resisting. While I find Senator Sanders’s concepts attractive and am personally pleased that many are being included in the Democratic Party’s platform, I am not the ideological purist I once was. Passion in pursuit of a political vision is vital, but I do not demand that all of my ideas be fully absorbed into the party’s DNA before I confer my vote. That hasn’t worked. Twice. The cost has been dear.

It is my experience that in American politics, absolutism leads to failure. Sanders’s supporters are driven by principle, but any reasonable reading of the past 50 years of American political history would bring them comfort in the recognition that they have already won, that more future victories are achievable in a Clinton presidency—and none under Trump—and that their guy is leading the way.

This election will be won or lost through voter turnout and voter suppression. Numbers matter. Bernie Sanders has exhorted his followers to vote for Clinton. For them to ignore him and sit it out or look elsewhere would run exactly counter to the vision Sanders has brought to the process. They should follow his lead and show up. The alternative is just not worth the risk.

And so we may avoid even a single term of Trump.