Bernie Sanders's electoral pitch rests on the notion that only he can bring to the polls young people and those traditionally not engaged with politics, but his Iowa and New Hampshire performances raise questions about that approach.

Yes, the Vermont senator can claim he started out the 2020 Democratic nomination fight strongly. Sanders, 78, has enjoyed a raw vote victory over his closest rival, Pete Buttigieg, though he's behind in pledged delegates from the Feb. 3 Iowa caucuses and the Feb. 11 New Hampshire primary.

Still, Sanders's vision of a Democratic electorate transforming into a left-wing movement remains elusive.

In numerous speeches at rallies in New Hampshire and Iowa, Sanders told supporters only his "is the campaign of energy, is the campaign of excitement, is the campaign that can bring millions of people into the political process who normally do not vote."

But, while the most populous states have yet to hold primaries, there's scant evidence to suggest the politically disengaged are coming out in droves.

Roughly 176,000 Iowans attended this month's caucus, which was about 5,000 more than in 2016. By comparison, 236,000 turned out for the 2008 caucuses, a 50-year high, when upstart Democratic candidate Barack Obama beat establishment favorite Hillary Clinton.

Entrance polls from this year's event showed a lower number of first-timers than in 2016, at 35%, compared to 44% in 2008. That year, 57% of Democrats polled said they were first-time caucusgoers.

Sanders did attempt to spin those facts his way, saying on Feb. 9 that he earned "huge voter turnout."

“The young vote, of people under 29 years of age, increased by 33% over where it was four years ago and was even higher than Obama’s extraordinary victory in 2008," he said, before adding that it was "a great omen for the 2020 campaign."

But Sanders was not referring to the number of new voters, just the proportion. As many as 10,300 fewer young people participated in the caucus this year.

In New Hampshire, Sanders's victory was undoubtedly aided by first-time and younger voters. Though that turnout set a new record at over 254,000 votes, exit polls found the Democratic electorate far less liberal than in 2016. Thirty-six percent of voters described themselves as moderate, a 9-point increase from 2016.

That helps describe Sanders's narrow victory of roughly 1.3% over Buttigieg and the late surge of Minnesota Sen. Amy Klobuchar. Sanders earned back the support of less than half of his 2016 voters, who delivered him a historic double-digit victory over Clinton.

Statistically, a vast number of those who ultimately supported Klobuchar or Buttigieg previously supported Sanders in the last primary cycle.

Political independents, once thought of as Sanders's strength, also broke in large numbers for Klobuchar and Buttigieg. Sanders's key to victory, in the primary, at least, may actually rest on the liberal base of politically active Democrats.

Heading into the Nevada caucuses on Feb. 22, the South Carolina primary on Feb. 29, and Super Tuesday on March 3, when 14 states and entities vote, Team Sanders can point to its enduring popularity among young people, though not at the margins his campaign boasts about in interviews.

With his heterodox coalition of supporters, Sanders may win a number of close primary victories, but it's far from the most effective way to win a majority of delegates before the Democratic National Convention convenes in Milwaukee, Wisconsin, in July.