Senator Bernie Sanders, an independent from Vermont and 2016 Democratic presidential candidate, smiles as he arrives to speak during a caucus night party in Des Moines, Iowa, U.S., on Monday, Feb. 1, 2016. Hillary Clinton is clinging to the narrowest edge over Sanders in the Iowa caucuses. Photographer: Andrew Harrer/Bloomberg via Getty Images

The New Hampshire primaries, which Bernie Sanders is winning by seventeen points at the time of writing, are the first test of the Clinton campaign's signature attack on Sanders: that he can't win the general election, so a vote for him is a vote for Ted Cruz or Donald Trump. Sanders's large victory suggests that the Clinton strategy didn't work, at least not yet.

But are the Clintons right? Could Sanders win the general election?

Over the weekend, Paul Krugman continued his New York Times campaign against Sanders in a column (on his New York Times blog) citing a Vox article that quoted six academics expressing doubts about Sanders's prospects in a general election. It was part of Krugman's larger crusade to convince readers that voting for Sanders would be an irresponsible capitulation to the heart in a season when the head should be in charge.

I was one of those six "experts." I said that it's hard to realign a party ideologically in a single election: It took 16 years for the New Right to go from Barry Goldwater's loss in 1964 to Ronald Reagan's win in 1980. And I still think that. But I think there are some very sensible reasons weighing on the pro-Sanders side of the equation.

Here they are.

1. Energy and turnout:

Sanders inevitably gets compared to Obama '08, and the Iowa Democratic caucus turnout (a bit lower than in 2008) suggested he may not have quite the same wave going yet; but the relevant comparator is obviously not Obama '08 but Clinton '16, and there's a straightforward case that Sanders's supporters would continue to be more on fire and mobilized in the general than hers. He certainly seems to be winning the enthusiasm race in the primaries. Also, it is possible, though a wild card, that Sanders might energize some of the formerly Democratic working-class voters who haven't gone Republican, but have just stopped voting.

2. The more they know him...:

It's been easy to say that Iowa and NH are welcoming states for Sanders, but they didn't look that way a year ago. He's come from way, way behind in both, and was almost universally regarded as a token candidate until sometime in the late fall. So, where voters have actually thought about the campaign, he's done extraordinarily well.

Skeptics tend to say there are two limits to this expansion of Sanders's appeal: ideological and demographic. Let's take them in turn.

3. Ideological:

Yes, some 50 percent of voters say they wouldn't vote for a socialist; but a lot of those are people who haven't thought about the word since the 1970s. We should take this profession of hostility even less seriously than pundits have taken the large share of young voters who say they like socialism, the Iowa Dems who say they identify as socialist, etc.

The term "socialist" is a wide-open one now, on account of a whole generation growing up with no memory of the Cold War, and on account of the Republicans' degrading it in attacks on Obama as a "socialist." You can bet that somewhere between half and three-quarters of those "I'd-never" voters are people who mean, "I'd never vote for that Obama!" Others may come to a different opinion when they realize Sanders is basically an FDR Democrat. And they may come to realize, now that the country increasingly admits that inequality and insecurity are very serious problems and that our eagerness for intervention abroad has been a disaster, they are ready for an FDR Democrat again.

4. Demographic:

The race question is an untested canard against Sanders at this point. Nearly everyone who has voted for him is white -- they're in Iowa and New Hampshire! Voters elsewhere aren't paying much attention yet. There's more than a little condescension in the common assumption that non-white voters are loyal to the Clintons, or to political machines that are wired into the Clinton apparatus. Recently, South Carolina numbers showed Sanders gaining ground faster among black voters than whites. We'll just have to see.

It's clear that Sanders's proposals on the racial aspects of criminal justice, education, infrastructure and health care, to name a few, would mean a great deal for many black voters (who disproportionately lack wealth and live in neighborhoods of concentrated poverty). These agenda items both continue the tradition of Dr. King's democratic socialism and coincide with the positions of groups like the NAACP and North Carolina's black-led, interracial Moral Mondays movement. If we agree with Ta-Nehisi Coates that the interests and priorities of black voters, not myths about them, are where we should start our analysis, Sanders seems awfully well positioned to get a hearing. The same goes for Latinos, who are heavily represented in the service unions and new labor efforts, like the Fight for 15, which have more interests and ideals in common with Sanders than with Clinton.

An afterthought on my suggestion that the 16 years between Goldwater's loss (1964) and Reagan's win (1980) suggests a one-cycle realignment is a tall order: That was a time of more stable party loyalties and a Democratic party that was more mainstream. The fact that the Republicans have gone far to the right while public sentiment has gone into flux but opened up to "socialist" ideas suggests an unusually fluid set of possibilities.

Finally, we should take seriously that this is a strange year, and remember that the events that have us asking about Sanders's viability in the general were big surprises. The smart money, so-called, didn't expect us to come to this point. So some epistemic humility and openness to further democratic surprise are in order!