Sen. Bernie Sanders (I-Vt.) earned the distinction of front-runner in the Democratic presidential field on Tuesday night when he edged out his competition in New Hampshire , just over a week after a popular vote win in the Iowa caucuses.

The win, predictably, has handed him the most coveted if least quantifiable gift in politics: momentum. Days after the victory, Sanders sped past former Vice President Joe Biden in an average of national polls . The local Culinary Workers Union, one of the most powerful forces in Democratic politics in Nevada and a critic of Sanders Medicare for All plan, announced Thursday that it is choosing not to endorse a candidate in Nevadas Feb. 22 caucuses. And on Friday, New York City Mayor Bill de Blasio endorsed Sanders , announcing plans to campaign for him in the Silver State.

But the narrowness of Sanders win in the Granite State he bested former South Bend, Indiana, Mayor Pete Buttigieg by a little more than a percentage point and the apparent failure of an overall increase in voter turnout to redound to his benefit, according to exit polls , spooked some Sanders partisans.

Bernie campaign its time to talk to the rural and old parts of the coalition, Michael Brooks, host of a popular left-wing podcast, tweeted as the primary results were coming in.

Some hard-core Sanders supporters went further, though, imagining a scenario in which the party could deny the Vermont senator the nomination if he arrived at the convention in Milwaukee this July with a bare plurality of pledged delegates. Reforms to the nominating process that Sanders pushed the Democratic National Committee to adopt prevent the elite group of elected officials and party insiders known as superdelegates from breaking with their states pledged delegates on the first round of voting. But all bets are off on the second ballot, when superdelegates, who are almost uniformly opposed to Sanders, reassume their freedom to vote their conscience.

Michael Kinnucan, a Brooklyn-based member of the Democratic Socialists of America, which has endorsed Sanders, laid out just such a doomsday outcome in a Facebook post on Tuesday night warning that the results are frankly pretty discouraging for the left.