Call me old, but ideological purity in presidential elections is an indulgence we cannot afford. 33% of Sanders Supporters Will Not Vote for Clinton If She Wins Nomination prompted this piece, although concerns about ideolical purity have worried me for many years.

I know many people do not like Hillary Clinton … and then there are those who hate her. Friends who know her well tell me she’s charming, fun, brilliant, etc. Alas, her winning side is not always evident.

Now I suspect Secretary Clinton will win the Democratic Party nomination. I also believe Senator Bernie Sanders (S-Vt.) will support her with vigor, and that many Sanders supporters will come around. But I worry about that last part, plenty.

Democrats—me included, but I’ll get to that—have a long history of imposing purity on our voting decisions, with very sad and bad consequences. The key races I’ve seen are Humphrey v. Nixon, Carter v. Reagan, and Gore v. Bush. Each went the wrong way, ideological purity was an issue, and in each instance we are still living with those consequences. (Consequences come in Part Two.)

In 1968 the Democratic Party imploded, nominated Vice President Hubert Humphrey, and we got President Richard Nixon. The election ended up being pretty close—Nixon won the popular vote by about 600,000 votes, out of 73,000,000 total votes—but Humphrey should have won it going away. Why? Almost 10,000,000 votes went to former Democrat, Alabama Governor George Wallace. If Wallace had not run, his voters would have almost surely voted for Nixon or stayed home. They were “race” voters, and Humphrey’s civil rights actions as Minneapolis Mayor in the late 1940s made his career.

Alas, Wallace was a given. So why did Nixon win? Dump the Hump was a liberal movement, brought forth out of anger over the Vietnam War. People criticized Humphrey for not moving far enough from the war his boss, President Lyndon Johnson, was committed to. And they stayed home on November 5, 1968. (For a terrific piece about Hubert Humphrey and the 1968 election, read Jump Up For the Hump by Hendrick Hertzberg for the New Yorker on June 1, 2011.)

In 1980 President Jimmy Carter ran for reelection against former California Governor Ronald Reagan and Representative John Anderson (R-Ill.), a moderate who ran in 1980 as an independent. Carter faced a primary fight with Senator Edward Kennedy (D-Mass.). The battle was brutal, and in the end Kennedy was a bad candidate trying to pull off—defeating an incumbent president in a primary fight—what has never been pulled off before or since.*

In the fall many Democrats stayed home again. Others voted for Anderson. In the end the race was never close; Ronald Reagan won by 2,000,000 more votes than Carter and Anderson got, collectively. What we will never know, though, is just how much the primary fight damaged Carter in the general election.

Then there was 2000. Vice President Al Gore ran against Texas Governor George W. Bush to succeed President Bill Clinton. Gore ran mostly away from Clinton, largely on account of Clinton’s personal foibles. In the end, Gore got 500,000 more votes than Bush, but he got them in the wrong places and lost, losing Florida, per the official count, by 537 votes out of almost 6,000,000 total votes.

So who got pure in 2000? The 97,000-plus Florida voters who voted for Ralph Nader. (Tony Robbins TED talk, Why We Do What We Do, has a great encounter with Gore at 5:25 and for the following couple of minutes, dashing the notion that 97,000 voter should have ever mattered.)

And me? I experienced Carter in 1976, working hard for Representative Morris Udall (D-Ariz.), my hometown Congressman, in the Wisconsin primary. I did not like Carter, what with his “I’ll never tell a lie” nonsense, and all of that piety. Carter won the primary, the nomination, and the November election. I voted for the first time, but I left the top of the ballot blank. And in 1980? I voted for Anderson.

I know I’m stretching a bit when I suggest “pure voters” are responsible for Nixon, Reagan, and W. I also know that, as a 19 and 23-year-old in 1976 and 1980, I was quite certain my statement—a blank ballot and a throwaway vote for Anderson—mattered. I also know, now, that I was wrong in 1976 and 1980, and that purity today will have dire consequences.

* Senator Eugene McCarthy (D-Minn.) seemingly ended President Johnson’s plans for reelection in 1968 by almost winning the New Hampshire primary. In fact, though, the president’s name was not on the ballot; thus, McCarthy almost beat a write-in candidate and, himself, was not the 1968 nominee.