As for Buttigieg, I likewise misjudged him. A small-city mayor in his 30s? Seriously? I was very doubtful. But he won credibility with raw political skills, not to mention by raising more money in the second quarter than any other Democrat, including Biden.

Buttigieg is also a masterful speaker, injecting nuance and thoughtfulness even into sound bites. He speaks not only Maltese and Norwegian, but also religion. Buttigieg is particularly deft at citing Scripture to highlight the hypocrisy of Trump and the G.O.P.

“So-called conservative Christian senators right now in the Senate are blocking a bill to raise the minimum wage,” Buttigieg noted Tuesday, “when Scripture says that whoever oppresses the poor taunts their maker.”

Buttigieg’s website is sketchy on policy, and his position on immigration is evolving. But in an off-the-record conversation, I found him more knowledgeable about issues than some other candidates I’ve spoken with.

Could he win a general election? Gallup found that 76 percent of voters reported that they would be willing to vote for a gay candidate, and 71 percent for one under 40. Clearly, he would lose some voters on both counts, but then again, even fewer Americans (63 percent) said that they’d be willing to vote for a candidate over 70 (as Trump, Biden, Sanders and Warren all are).

One reason for skepticism about this entire column: Both Warren and Buttigieg are unproven among national voters, and there’s a risk that their cerebral qualities will antagonize some voters. Warren has not been particularly popular even in her home state, liberal Massachusetts, and the RealClearPolitics polling average shows her only 2.4 points ahead of Trump in head-to-head polls, compared with 4.5 points ahead for Bernie Sanders and 8.1 points ahead for Biden. Buttigieg does even worse, running only a hair ahead of Trump in head-to-head polling; it’s fair to object that pairing two middling performers is not an optimal strategy.

Yet while Biden is seen in many quarters as the safest Democratic candidate, I’m wary. This is a moment when only 37 percent of Americans say that the country is on the right track, yet Biden represents continuity of the politics of the last few decades — missing the opportunity for a change candidate.

This entire reverie is, of course, ridiculous, and Buttigieg and Warren still must demonstrate an ability to win over actual voters. But for brilliance, eloquence and the ability to embody change, they would constitute a historic partnership.

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