The larger lesson from 1960 is that even a rare consensus nomination does not come easily. Odds are also great that, as with Nixon, Clinton’s scars from the political wars would prevent an unimpeded coronation and produce a difficult fall campaign. Despite enthusiasm over the possible election of the first woman president and appreciation for her long record of service, many progressive Democrats will focus yet again on her vote to authorize the Iraq war and, in a party that has unmistakably moved leftward in the last decade, the ties to her husband’s more moderate philosophy, at least as it was articulated in the 1990s.

Political factions rarely die. They fade away for a while only to reappear in new forms. The Obama-Clinton divide of 2008 may be hidden of late, but some similar fissure may well reemerge in 2016.

One hidden divide is generational. Obama’s victory over Clinton in 2008 seemed to be almost a passing-the-torch moment from one American era to the next. In a much-discussed magazine article in late 2007—just as Obama was gaining ground on Clinton—commentator Andrew Sullivan argued that Obama’s candidacy could allow the country to say “Goodbye to All That,” meaning the Baby Boomer-inspired cultural and political wars of the late 20th century. A Clinton nomination would put the presidency, and the Democratic Party, squarely back in Boomer hands. Which raises another comparison to Nixon: His presidential nominations in 1960 and 1968 were broken up by the far more conservative campaign of Barry Goldwater in 1964. After the party embraced the right, it scurried back to the establishment four years later. A Clinton nomination, post-Obama, would be another “back to the future” moment when the party, after a shift to Obama’s promise of a new kind of politics, turned back the clock to the Clintons. Still, the generational argument is one available to a possible Clinton challanger.

For now, Clinton looks indestructible to many, leading Time magazine to ask in a recent cover story—complete with a navy pantsuit and polished black heel crushing, presumably, the presidential dreams of any putative rival—“Can Anyone Stop Hillary?” The answer could be as simple as her husband. Bill has been involved in myriad business and charitable activities since leaving office, and it’s conceivable that there are worse imperfections in his recent past than the money maneuverings of Doug Band, his longtime close aide.

It is too soon to know for sure who would run against Hillary Clinton, but modern history certainly suggests there will be a field of three or four. From 1948 to 2012, the average number of Democratic presidential candidates was about 3.5, once very minor and favorite-son candidacies are discarded.

Republicans have had close to the same number of serious presidential candidates, about 3.2 per year, since World War II. And in slightly more than half (nine) of the 17 elections during this time period, and six of the last seven, the GOP had more serious candidates trying for the brass ring than did the Democrats. The old stereotype of Republicans as the more orderly, managerial party is false—though in recent years, the Tea Party has disabused most observers of that notion anyway.

Sure enough, from this early vantage point, it looks very likely that the GOP will field considerably more candidates in 2016 than will the Democrats, with Chris Christie, Marco Rubio, Scott Walker and half a dozen others waiting in the wings. But it’s also likely, or at least more likely than most seem to think, that there will be more of a Democratic contest than currently appears on the horizon.

The White House is rarely handed to anyone, and only then through tragedy and vice presidential succession. And Hillary Clinton knows this as well as any person alive.