The choice of a vice president rarely tips an election, but in 1960 it surely did. (When a race is as close as 1960—Kennedy beat Nixon by 0.2 percent—any number of things can tip the election.) Johnson proved to be a zealous and effective campaigner, even as he privately badmouthed Kennedy to reporters. His firm control of the Texas state party organization was critical to the Democrats' success there. His very presence on the ticket probably helped the Democrats win six other Southern states that would soon become reliably Republican.
If Johnson's value to the Democrats in 1960 is undeniable, George Bush's importance to Ronald Reagan's victory in 1980 is less clear-cut. But it, too, showed the wisdom of reconciliation after a hard-fought nomination battle. One of the most hostile altercations came just before the New Hampshire primary. Bush, having won the Iowa caucuses, wanted to debate Reagan one-on-one, but he then refused to share the costs, leaving Reagan to foot the bill. (Outside sponsorship might have constituted a donation to the two front-runners' campaigns.) But on the night of the debate, Reagan showed up with the other Republican contenders in tow. When the moderator, a local newspaperman named Jon Breen, tried to silence him for speaking up on behalf of the excluded Republicans, Reagan memorably growled, "I'm paying for this microphone, Mr. Green." (Reagan, it happens, was recalling an eerily apt line from Spencer Tracy in State of the Union, accounting for why he altered the moderator's last name.) The footage of an aggressive Reagan and a paralyzed Bush played on TV news for another 48 hours—humiliating Bush and confirming in Reagan's mind his adversary's reputation as a wimp. Reagan took New Hampshire easily.
Apart from John Anderson, an old-style liberal Republican who stayed in the race as a gadfly, the other candidates soon dropped out. Though Reagan won most of the remaining contests, Bush stayed competitive throughout the spring. He continued to do well among party regulars troubled by Reagan's often strident right-wing rhetoric, his lack of foreign-policy experience, and his divisive presidential bid at the 1976 convention, which some felt had contributed to Gerald Ford's ultimate defeat by Jimmy Carter. Stressing his own conservative credentials, Bush tried to define his opponent as out of the mainstream—famously mocking his embrace of what Bush called "voodoo economics." But Reagan soldiered on, and in late May, Bush dropped out.
Bush would have been the natural choice for vice president had not efforts been made to create a different "dream ticket"—one with former President Ford as Reagan's understudy. The Reagan-Ford negotiations rivaled the Kennedy-Johnson dance of 1960 in their intricacy, but they finally crumbled when Ford said in a live interview with Walter Cronkite that he envisioned something like a "co-presidency" (Cronkite's term). As a result, any reconciliation between party regulars and conservative activists came to rest on the selection of Bush.
Some players on both sides wondered if Bush, who had supported the Equal Rights Amendment and abortion rights, could run with a man who opposed both. And Reagan personally harbored other doubts. "If he can't stand up to that kind of pressure," he said to an aide, referring to the New Hampshire debate, "how could he stand up to the pressure of being president?" But the need for unity prevailed. When Reagan called with the offer, Bush happily agreed to endorse the party's (anti-abortion, anti-ERA) platform "wholeheartedly," and the two went on to victory. Although Reagan's 44-state blowout suggested that any running mate would have sufficed, the choice of Bush did, at a minimum, help make him palatable to moderate voters.
It's unclear whether Obama shares the qualities that Kennedy and Reagan showed in forging their unity tickets: the self-assurance not to fear being upstaged, the magnanimity to overlook the primary-season fisticuffs. And it's equally unclear whether Clinton would even want to sit through eight years of an Obama presidency and then, at age 68, endure another 16 months of hell of the sort she's now finally concluding—with no greater chance of emerging victorious. Surely, for her, the more gratifying course would be to achieve the historical first of having her name placed in nomination for the presidency at the Democratic convention and gaining a near-majority of ballots. With dignity, she could then pursue other distinctions, whether Senate majority leader or associate justice of the Supreme Court.
Then again, in 1960 the smart money said that Lyndon Johnson would never settle for the vice presidency, either.