Biden Is Back: This Week in the 2020 Race

In just seven days, the Democratic race has changed almost beyond recognition. Let’s catch you up on the biggest week of the campaign so far.

We know the South Carolina primary might seem like ancient history, but it was actually only last Saturday. So it’s worth remembering where the race stood going into it.

Eight days ago, Senator Bernie Sanders of Vermont was the clear front-runner for the nomination, having basically tied in Iowa, won in New Hampshire and blown the rest of the field away in Nevada. South Carolina was always going to be more challenging for him, but he was polling competitively with former Vice President Joseph R. Biden Jr. there, and if needed, he had Super Tuesday right around the corner to lift him back up.

A week ago, Mr. Biden was lagging in polls of Super Tuesday states. But South Carolina reshaped the race exactly as Mr. Biden had hoped.

Aided by several competitors’ withdrawals and endorsements, Mr. Biden dominated states he was expected to win narrowly, won states he was expected to lose and topped it off with victories in places he hadn’t even visited.

All told, he won 10 of the 14 states that voted on Super Tuesday, while Mr. Sanders took Colorado, Utah, Vermont and probably California. (Mr. Sanders leads there, but the race has not been called.) California is a big deal — it awards far more delegates than any other state — but that doesn’t change the reality coming out of Super Tuesday: While the race certainly isn’t over, Mr. Biden is now the front-runner.

The results were devastating for Senator Elizabeth Warren of Massachusetts, who finished third in her home state and whose delegate haul was in the dozens, while Mr. Biden and Mr. Sanders won hundreds. They were also a stinging rebuke to former Mayor Michael R. Bloomberg of New York, who had gambled hundreds of millions of dollars on the idea — incorrect, as it turned out — that he could seize moderate voters from Mr. Biden.

Five candidates ended their campaigns in the past week, in this order:

The dropouts reflected, over the course of just a few days, a decisive consolidation around one standard-bearer in the centrist wing of the Democratic Party, Mr. Biden, and one on the left, Mr. Sanders. (Representative Tulsi Gabbard of Hawaii is still in the race, but she is averaging less than 1 percent in polls and has won only two delegates, both from American Samoa.)

Idaho, Michigan, Mississippi, Missouri, North Dakota and Washington will all vote on Tuesday.

Michigan is particularly important because it is the first of the former “blue wall” states — the ones that decided the 2016 election — to hold its primary. (The other two, Pennsylvania and Wisconsin, won’t vote until April.) The Democratic nominee will almost certainly need to win back those states to beat President Trump, and Mr. Sanders is focusing heavily on them: On Thursday, he canceled a rally in Mississippi to go to Michigan.