Vermont Sen. Bernie Sanders won the Democratic primary in New Hampshire on Tuesday night — but he didn't win it with anything close to enough decisiveness to dispel fears that the party's path to settling on a nominee is going to be a long and grueling process with an outcome that's far from clear or obvious.

Four years ago, Sanders prevailed over Hillary Clinton in New Hampshire with 60.1 percent of the vote. On Tuesday, Sanders was projected to win with just 26 percent. Of course, he was running in a much more crowded field this time around. On the other hand, he's from a neighboring state and the candidates who finished second and third— former South Bend, Indiana Mayor Pete Buttigieg and Minnesota Sen. Amy Klobuchar, respectively — are Midwesterners who are much less well known. The fact that Buttigieg effectively tied Sanders in Iowa and trailed the democratic socialist by less than 2 percentage points in New Hampshire is a sign that Sanders' candidacy is very far from putting away the competition.

Sanders' position appears even weaker when we combine his showing with that of fellow left-liberal Massachusetts Sen. Elizabeth Warren, who finished in fourth place with just over 9 percent of the vote, and compare it to the combined total won by the moderates Buttigieg, Klobuchar, and former vice president Joe Biden, who finished in fifth place with around 8.5 percent of the vote. This consolidated ideological contest has the left losing to the moderates by roughly 52 to 35 percent. That isn't even close.

But that way of thinking about the contest isn't especially illuminating, as those of us who watched the 2016 GOP primaries unfold up close will recognize and remember. For much of that electoral season, Donald Trump won primaries and caucuses, but not by wide margins, leaving members of the Republican establishment hopeful that the not-Trump vote would eventually consolidate to overwhelm his insurgent candidacy.

As we all know, it never happened — and that should give the Sanders campaign and its cheerleaders considerable hope. (That Sanders' strongest rivals coming out of New Hampshire, Buttigieg and Klobuchar, will likely struggle to compete in South Carolina and across the vast number of states voting on Super Tuesday is a powerful advantage.)

Yet Sanders' position is actually quite a bit weaker than Trump's was four years ago. Trump won New Hampshire (after losing Iowa to Texas Sen. Ted Cruz) with 35.2 percent. Over the next several weeks, pundits pointed out that Trump was unlikely to win the primaries because, aside from an impressive 45.7 percent showing in the Nevada caucuses, he appeared to have a ceiling of around 35 to 37 percent. The combined votes for Cruz, Florida Sen. Marco Rubio, and Ohio Gov. John Kasich regularly beat Trump's showing alone. Surely that meant that one of them would eventually emerge to challenge Trump singularly and trounce him.

But it wasn't to be. The three not-Trump candidates stayed in long enough for Trump to begin winning by bigger margins — first with 40.6 percent of the vote in several contests on March 15, next with 43.9 percent in eight contests over the following month, and then a 56.5 percent majority in five primaries on April 26. In the end, Trump won 44.9 percent of the vote — more than enough to prevail in the delegate count because of the GOP's use of winner-take-all delegate allocation.

Not only do the Democratic primaries use proportional delegate allocation instead of winner-take-all, but Sanders' initial ceiling is quite a bit lower than Trump's (26 percent instead of 35 percent). Part of that might be because Sanders faces a larger and more fractured field — with the potentially biggest fracture of all (the self-funded candidacy of erstwhile Republican billionaire Michael Bloomberg) still waiting in the wings. As it did four years ago, the lack of cohesion in the field could benefit Sanders by preventing any other candidate from overtaking him — especially if his ceiling begins to rise over the next few contests. Though it could also hold down his delegate totals, easily preventing him from winning enough to lock down the nomination prior to the party's convention in July.

But Sanders could face an even bigger problem — the fact that the Democratic electorate isn't fractured enough.

Trump benefited enormously from the fact that, while Cruz and Rubio were establishment Republicans, Cruz was competing directly against Trump for the title of the most anti-establishment candidate in the race. That kept any one of the not-Trump options from gaining serious traction.

The dynamic among the Democrats is very different. Sanders is the only anti-establishment candidate running, with Warren only sometimes seeming to compete with him for that title. The rest of the field — including Bloomberg — displays very little animosity toward the Democratic powers-that-be. That, combined with the electoral strength of ideological moderation in the party, is likely to make consolidation of the not-Sanders vote relatively easy, at least compared with what the Republicans went through four years ago.

After Iowa and New Hampshire, Sanders is clearly in the lead. But the margin is small, and the obstacles to victory are enormous.

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