EXPLAIN TO ME HOW SANDERS LOSES THE NOMINATION

In the immediate aftermath of the Iowa caucuses, some observers looked at partial results and declared Pete Buttigieg the winner. Now, however, with more votes counted, Bernie Sanders leads on first-ballot votes, leads on final-alignment votes, and ties Butiigieg on likely convention delegates. Elizabeth Warren exceeded expectations but finished third, well behind the leaders. Joe Biden continues to trail Warren.

In New Hampshire, Sanders has a solid lead -- 8.5 points, according to the Real Clear Politics average -- but Buttigieg appears to be surging. In the past two days, Buttigieg has gained 9 points in the WHDH/Emerson College tracking poll, and 8 points in the Boston Globe/Suffolk University tracking poll. In both polls, Biden and Warren are well behind the leaders.

But Buttigieg is competing with Biden and Amy Klobuchar for moderate votes in New Hampshire. Maybe non-progressive voters will abandon those two and rally around Buttigieg -- but what happens then? Buttigieg needs support from non-white voters to be competitive in the next two states, Nevada and South Carolina, and he doesn't have it -- RCP has him at 7% in Nevada and 5.5% in South Carolina. Biden has a slim lead in both states, but Sanders is coming on strong in both -- as is Tom Steyer, of all people, in South Carolina.

What happens if Biden gets shellacked in New Hampshire? Can he win Nevada? And if he loses in both states, what will older black voters in South Carolina do? They like Biden for a number of reasons, but one of the most important is that they think Rust Belt whites will also vote for him in a race against Trump, whom they're desperate to beat. If they stop believing white people will vote for Biden, will they bother to vote for him? And if not, where will they go? I think they'd defect, but I have no idea who'd pick up their votes.

In states after South Carolina, Mike Bloomberg will be competing -- and he's starting to show some polling strength: Morning Consult has him tied with Warren for third nationwide, with 14% of the vote, and also tied for third with Warren in Super Tuesday states, also with 14%. Morning Consult also says he beats Trump by 7 -- the best showing of all the big-name contenders. (Biden and Sanders lead by 4, Warren and Buttigieg by 1.)

But after the first four states, Sanders might seem to have a commanding lead -- and Sanders-averse moderates might continue splitting their votes among Buttigieg (who'll probably continue to struggle with non-white voters), Biden (who might not win any of the first four states but probably will stay in the race through Super Tuesday regardless), and Bloomberg. Warren will be near the top, but she doesn't seem poised to win any state except her own, and her presence in the race no longer seems to be a drag on Sanders.

I don't see how this doesn't lead to a Sanders victory -- which worries me because Sanders didn't generate a youth voting surge in Iowa. If he can't do that, can he win in November? (The head-to-head numbers in the Morning Consult poll and elsewhere suggest he can, though he's not the strongest possible opponent.)

Could Bloomberg, of all people, pick up older non-white vote if Biden falters? It's not crazy to think so -- in the last Quinnipiac poll, in which Biden had 52% of the black vote among Democrats, Bloomberg had 8%. 7%. (Buttigieg had zero. Sanders had 15%, and I bet they're mostly millennials.)

So I think Sanders is the clear favorite now. Anyone else have an alternate scenario?