Sen. Bernie Sanders (I-Vt.) is without question the most progressive of the Democrats running for president. And yet he’s arguing that he is in fact the candidate most able to persuade Trump voters — or more specifically, those sainted white working-class men from the “heartland,” where the truest of Americans supposedly reside.

Sanders is not the only one making this claim. It’s is an idea worth interrogating, not just which (if any) of the candidates can persuade these voters but also what it means to pursue them and what kind of candidate is supposed to be able to do so. Let’s begin here:

The blistering attacks on the president reflect Sanders’s developing, and arguably risky, strategy of reaching out to Trump’s voters — people the president has said would support him even if he shot someone. It’s a sharp contrast with other Democratic candidates who are focused on mobilizing Trump opponents. Not incidentally, it is also a way to signal to Democrats that Sanders is their best hope for knocking off Trump, at a time when many fear he is the opposite.
The most striking example of this strategy will play out Monday night when Sanders appears at a town hall meeting hosted by Fox News Channel, an outlet many Democrats detest and one the party has blocked from hosting a debate. Sanders says it’s important to talk to Fox viewers directly and tell them Trump misled them.

I have to doubt that Sanders actually believes that he’ll persuade Fox viewers to vote for him by going on the network, which has become little more than a propaganda arm of President Trump’s administration. But he wants to be seen doing it by people who are not actually Fox viewers, as a demonstration of his eagerness to reach out.

While it may be inevitable that we get caught up in this argument, I have to repeat what I’ve long argued, that there’s something inherently problematic in making judgments about electability. That’s not just because people are usually pretty bad at it, but also because it means that instead of deciding which candidate you like, you’ll base your vote on which candidate you think other people will like.

But you have to give Sanders credit for one thing: He’s arguing against the widespread yet unsupported belief that the only way for a Democrat to win any Republican votes is with milquetoast policy centrism. That belief rests on the idea that voters make their decisions by assessing each candidate’s ideological position, and the candidate closest to the center is the one who wins. It’s what political scientists refer to as the Median voter theorem, and the problem is that in practice it doesn’t work very often. So Sanders deserves some credit for pushing back against that idea, even as it’s embraced by candidates and potential candidates such as former Colorado governor John Hickenlooper and former vice president Joe Biden.

But they’re not the only ones talking about reaching out across the middle. There’s South Bend, Ind., Mayor Pete Buttigieg:

Underscoring themes of generational change and his interest in reaching out to religious voters and working-class voters who drifted toward Trump have been priorities of Buttigieg and his aides as they have mapped out his campaign, believing he can make overtures to them and liberal Democrats at the same time.

Buttigieg’s strategy for reaching out to working-class whites is at this stage, like most things about his campaign, nice-sounding but vague. But what do these candidates have in common? They’re white men.

In the most diverse field in presidential campaign history, that’s the unspoken assumption here: Four years after Trump won the presidency on a campaign built on rancid xenophobia, racism and misogyny, there’s just no way a woman or a person of color could win over any significant number of people who voted for him. If anyone can do it, it’s going to have to be a white man. A woman or a person of color would just generate too much antipathy from those voters.

Whether that’s true is as yet an open question, although I would point out that, just as he did in 2016, Trump will make 2020 a referendum on race no matter who the Democratic nominee is. And at this point, Democrats are the party of a diverse America, no matter who they nominate.

This is part of a debate going on within the Democratic Party about whether mobilization (getting your own voters to the polls) or persuasion (persuading members of the other party to vote for you) is the better way to win elections, particularly presidential elections. For their part, Republicans decided that question long ago; they never bother attempting to persuade Democratic voters to vote for them. Every Democratic candidate would say “We can do both!” because that’s the kind of thing candidates are supposed to say, but in practice it’s quite a bit more complicated. There’s a cost to spending too much time “reaching out” to voters who are almost certainly not going to vote for you, because it can be a bunch of wasted effort that produces no results at the same time as it threatens to make your own supporters less excited.

Sanders may feel that chasing Trump voters isn’t a risk for him, because there’s no doubt that his base of support is more enthusiastic than that of any other candidate. But that doesn’t necessarily mean that, if he were the nominee, he’d generate more excitement among the much broader Democratic base than another candidate would. It’s entirely possible that the party as a whole would be more energized by Kamala D. Harris or Elizabeth Warren or Beto O’Rourke or somebody else.

At this point, there’s almost no way to know. But no matter how much you might want to defeat Trump, it’s a much better idea to think about which candidate you like, rather than try to predict which candidate might be able to appeal to some white guy sitting in a diner in Waukesha, Wis. That seldom ends well.

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