The Goldwater nomination left conservatives in the GOP with the power to nominate one of their own every four years, or to veto any non-conservative.

Early in Ronald Reagan’s second term, Bill Rusher, the publisher of National Review, was interviewing the president in the Oval Office for a documentary on the conservative movement.

Rusher asked how he would describe Barry Goldwater’s role.

Reagan thought a moment and replied: I guess you would have to call him the John the Baptist of our movement.

I resisted the impulse to lean in and ask, “Sir, if Barry Goldwater was John the Baptist, who would that make you?”

The death of George McGovern brought back thoughts of these two men who suffered two of the greatest defeats in presidential history.

McGovern was an unapologetic liberal from South Dakota. Goldwater was Mr. Conservative and proud of it. Both had been World War II pilots. Goldwater had flown “over the hump,” the Himalayas, into China. George McGovern flew bombing runs over the Ploesti oil fields.

McGovern had been at the Progressive Party convention in 1948 that nominated Henry Wallace to run against Harry Truman. Goldwater voted against the Senate censure of Joe McCarthy in 1954 and was one of only six Republicans to oppose the Civil Rights Act of 1964.

In 1964, Goldwater led his party to a 22-point defeat at the hands of Lyndon Johnson, winning only five states of the Deep South and Arizona.

Eight years later, McGovern lost every state but Massachusetts to Richard Nixon in the worst rout ever sustained by a nominee of his party. In 1984, McGovern would be joined in that dubious distinction of a 49-state defeat by Walter Mondale.

Yet unlike others who have lost presidential bids in modern times — Mondale, Michael Dukakis, Bob Dole, Al Gore, John Kerry, John McCain — Goldwater and McGovern proved to be men ahead of their time.

Though a reluctant candidate who had to be “drafted,” Goldwater became the political instrument of a rising conservative movement that used his campaign to tear the Republican Party away from an Eastern liberal establishment that had controlled it for generations and dictated its nominees.

In 1960, Vice President Nixon had traveled to New York to cut a deal with and mollify Nelson Rockefeller. But by 1968, it was the endorsement of Goldwater and conservatives like John Tower of Texas and Strom Thurmond of South Carolina that were Nixon’s keys to the nomination. After 1964, the liberal establishment never again imposed a nominee on the GOP.

But between the movement that captured the nomination for Goldwater and the cause that captured the Democratic Party for McGovern, there were differences not only of philosophy.

The Goldwater people were rebels. They wanted to overthrow and displace the old leadership. Many McGovernites were revolutionaries.

Where conservatives sought a party more true to its principles, many McGovernites wanted to change America into another country — more statist, egalitarian, permissive. They did not like the country they grew up in. The Goldwaterites wished to restore the best of those times.

“Why Not Victory” was the title of Goldwater’s book on the Cold War. “Come Home, America” was McGovern’s slogan.

Where McGovern sought to end the war in Vietnam, some of his supporters thought America was on the wrong side of that war and on the wrong side of the Cold War. They marched under Viet Cong flags, chanting: “Ho! Ho! Ho! Chi Minh — The NLF is going to win.”

With McGovern’s nomination, conservatives in the Democratic Party who had voted for George Wallace or Hubert Humphrey in 1968 moved in the millions into Nixon’s New Majority and would remain there until the end of the Cold War. They became the Reagan Democrats.

Whatever McGovern’s personal views, his campaign became the vehicle of the counterculture of the 1960s, of the feminist and homosexual rights movements, of antiwar activists and student radicals, of Harvard and the Hollyleft, all of whom were in those years cordially detested by Middle America.

Goldwater’s nomination ripped the Republican Party asunder. But Nixon, the most skillful politician of his generation, was able to stitch it back together by 1968 to win the presidency.

McGovern’s nomination run replicated Goldwater’s. His people had written the rules for the 1972 delegate selection process and written the bosses out. The nomination would be decided in state conventions, caucuses and primaries, as it was in the Goldwater campaign.

The Goldwater nomination left conservatives in the GOP with the power to nominate one of their own every four years, or to veto any non-conservative. No Republican ticket after Goldwater would be without a conservative. In 1976, the right would force Gerald Ford to dump his vice president, Nelson Rockefeller, as the price of its support.

McGovern’s followers never captured the presidency, as the right did with Reagan. But the counterculture for which his campaign was the earliest political expression became the dominant culture of America’s social, cultural and intellectual elite. We live with the consequences still.

And only that altered culture could have opened the door of the presidency to a man of Bill Clinton or Barack Obama’s background.