First Read is your briefing from "Meet the Press" and the NBC Political Unit on the day's most important political stories and why they matter.
WASHINGTON — A lot sure has changed over the last week in American politics.
Last Friday — before South Carolina — Bernie Sanders was the clear Democratic frontrunner and was being viewed as the possible/likely nominee.
Also last week, President Trump's re-election numbers were looking as strong as ever, with a Marquette Law poll showing his approval rating in battleground Wisconsin at 48 percent.
Joe Biden, after his decisive victories in South Carolina and on Super Tuesday, is your Democratic front-runner.
And Trump's fortunes sure look gloomier for the coming months, with the spread of coronavirus in the United States — and the health and economic toll it could leave as the president faces re-election eight months from now.
It was 40 years ago when another U.S. president facing re-election — Jimmy Carter — encountered a slow-moving crisis (the Iran hostages) that dominated the full year before Election Day.
And the challenge for Trump is how he deals with a coronavirus story that doesn't look like it will end anytime soon.
Here's why the remaining delegates in California aren't going to change the overall leader
On Wednesday night, Bernie Sanders told MSNBC's Rachel Maddow that the outstanding delegates in California could still make him the overall delegate winner from Super Tuesday.
"At the end of the count in California, where we have won and will win a whole lot of delegates, I think at the end of the day, we may be a little bit ahead of Biden."
But here's the math why the remaining California delegates won't push Sanders into the lead.
Right now, according to the NBC News Decision Desk, Biden holds a 69-delegate lead over Sanders, 595 to 526.
And yes, there are still 151 delegates remaining to be allocated in California, where Sanders is currently ahead of Biden by a 34 percent-to-25 percent margin.
But there are also a total of 104 delegates still to be allocated from the other 13 Super Tuesday states, including 24 in Texas (which Biden won), 11 in Massachusetts (ditto), nine in North Carolina (ditto again) and Alabama (ditto).
What's more, assuming that Sanders' lead in California remains 9 points or so, that comes out to — roughly — a 58 percent-to-42 percent delegate split.
And dividing up the remaining 151 California delegates that way gets you: 88 delegates for Sanders, 63 for Biden.
That's not enough to overcome Biden's current delegate lead.
2020 Vision: Elizabeth Warren's big, structural mistakes
Yes, Elizabeth Warren's supporters can blame sexism for her poor showing in the early 2020 Democratic contests.
And they can also blame a political media that asked more questions about how she'd pay for her health-care plans than they asked of Bernie Sanders.
But you also need to acknowledge the campaign's big tactical mistakes.
Why did Warren embrace Sanders on Medicare for All - "I'm with Bernie" — when she previously said that the most important thing to do was defend the Affordable Care Act? (NBC's Benjy Sarlin — below — has more on Warren and Medicare for All.)
Why didn't she try to draw more distinctions with Sanders — until it was too late? (If she was going to win the nomination, she needed to beat Bernie in Iowa and elsewhere.)
Why did she make purity-in-fundraising such a priority — only to refuse to reject SuperPAC support in her campaign's final days?
And why did she take that DNA test in the first place?
Warren had a great political message, and she's a top-notch political athlete.
But she and her campaign weren't well-served by those strategic decisions.
On the campaign trail
Today: Bernie Sanders holds a rally in Detroit at 7:00 p.m. ET… And Amy Klobuchar stumps for Joe Biden in Michigan, hitting Detroit and Southfield.
Saturday: Biden visits St. Louis… Sanders rallies in Chicago… Jill Biden stumps in Florida… And Amy Klobuchar remains in Michigan.
Sunday: Biden is in Jackson, Miss., with Viveca Fox… Sanders, in Michigan, does rallies in Grand Rapids and Ann Arbor… And Jill Biden remains in Florida.
Dispatches from NBC's campaign embeds
The fight for Elizabeth Warren's endorsement and supporters is on, and NBC's Gary Grumbach has Bernie Sanders' comments yesterday in Arizona: "Some of you know, Sen. Elizabeth Warren, a good friend of mine, dropped out today. And I want to take this opportunity to applaud Sen. Warren for a strong issue-oriented campaign. And tonight, tonight, we invite Sen. Warren supporters into our campaign, because I think they will find many of the issues that Warren campaigned on are exactly the issues that we are fighting for," Sanders said.
And what comes for Andrew Yang? NBC's Julia Jester reports it may include New York City: "Andrew Yang is seriously considering a run for New York City mayor, according to a source familiar with Yang's thinking. Yang has spoken with Mike Bloomberg since he dropped out of the 2020 race yesterday - specifically about a NYC mayoral bid."
Data Download: The number of the day is … 60 percent
That's the share of Bernie Sanders voters who say they have reservations or are very uncomfortable with Joe Biden, according to merged data from the NBC News/WSJ poll from January and February. Only about four-in-10 say they are enthusiastic (just 7 percent) or comfortable (31 percent) with the former VP.
That's a far more negative rating than Biden fans have for Sanders. A majority — 55 percent — of Biden backers say they're enthusiastic or comfortable with Sanders, while 44 percent disagree.
So if you're wondering why President Trump keeps expressing sympathy for Sanders voters who he says are getting a raw deal… et voila.
Tweet of the day
Talking policy with Benjy
Elizabeth Warren edition: It's been driving supporters of Elizabeth Warren crazy for months. Warren embraced Medicare for All, and even filled in crucial details Bernie Sanders left out of his own bill, and was dragged down by attacks from all sides. Sanders, who "wrote the damn bill," enjoyed a resurgence that put him on the cusp of the nomination before Biden's comeback. Why did this issue work for one, Benjy Sarlin asks, but not the other?
To many Warren supporters, there was a sexist double standard at play in the campaign and the press, one that demanded more and more details from her and only broad talk of revolution from Sanders.
"Everyone else could have different plans," Democratic strategist Rebecca Katz said, "but she had to explain every single thing on every single plan because she was perceived as 'The Candidate With Plans.'"
But there were other factors that made her more vulnerable to attacks too. Her voters skewed college-educated and suburban and were less likely to be uninsured and more likely to be nervous about electability concerns. The issue also distracted from the simple winning pitch she rode early in the race: A wealth tax on billionaires to fund education and child care benefits for the upper middle class and lower incomes. Instead, she found herself explaining a health plan whose benefits and tradeoffs were more complicated.
All this put her in a difficult spot politically. She had taken a risky position to win over voters on the left, but they remained attached to Sanders, who was also critical of her plans to finance Medicare for All and split it into two bills. Meanwhile, her competitors to the middle decided her voters were easier to peel off than Sanders' hardcore base, and relentlessly attacked her on the issue.
The Lid: And then were two
Don't miss the pod from yesterday, when Liz Brown-Kaiser reviewed the state of the race on the day Elizabeth Warren ended her campaign.
ICYMI: New clips you shouldn't miss
The big dilemma for Elizabeth Warren now that she's out of the race: Will she endorse? Who? And when?
Bernie Sanders cancelled a speech in Mississippi aimed at black voters as he turns instead to the all-important state of Michigan.
Mike Bloomberg is planning a large new organization to support the Democratic nominee.
From the New York Times: "As Bernie Sanders Pushed for Closer Ties, Soviet Union Spotted Opportunity."
Trump Agenda: President versus the experts
President Trump continues to contradict his own experts when it comes to the coronavirus.
A federal judge is blasting Bill Barr's disclosure of the Mueller report from last year.
Former GOP congressman Aaron Schock came out.
More documents show big payments from the Secret Service to Trump properties.
2020: Biden and the African-American vote
Why did black voters choose Biden on Super Tuesday so overwhelmingly?
Young Bernie Sanders supporters might be worried about their candidate's chances this time, but they say the movement he's built will outlast 2020.
A man held up a Nazi flag at a Sanders event in Phoenix last night.