Warren, by contrast, has been rolling out substantive, detailed policy proposals — many, many substantive, detailed policy proposals. Traditional punditry says that this should be a turnoff, that voters’ eyes will just glaze over at the proliferation of white papers.

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But Warren has managed to turn relentless wonkery into a defining aspect of her political persona. Supporters show up at her rallies wearing T-shirts that proclaim “Warren has a plan for that!” And she is, by all accounts, managing to make earnest policy discussion a way to connect with her audiences.

In a way, the closest parallel to the Warren phenomenon — although it’s one I hate to draw — was the temporary rise of Paul Ryan, former speaker of the House (remember him?). Like Warren, Ryan built himself up by cultivating an image as a smart policy wonk.

But even aside from the fact that Ryan’s basic agenda was to take from the poor and give to the rich, he was a phony, whose proposals didn’t add up and didn’t address real problems. Warren, by contrast, is the real deal. You don’t have to support the specifics of her plans to realize that they’re the product of hard thinking, drawing on the work of respected economic researchers.

In that case, however, why haven’t other presidential contenders been rolling out comparable plans? The answer, I’d suggest, is that Warren — herself a significant policy scholar — understood from the beginning something that other candidates are only beginning to grasp: The difference between being serious and being Serious.