But then Rep. Jim Clyburn (D-South Carolina) endorsed Joe Biden. That endorsement helped Biden to score a huge victory in South Carolina. And it carried over to Super Tuesday, when Biden won 10 out of the 14 states voting.
That revealed a weakness in the Sanders campaign -- he has trouble attracting Black voters (just like he did in 2016). That's a problem, since Blacks make up a significant share of Democratic Party voters. Clearly, Sanders needed to somehow change that dynamic.
On Sunday, he got some help. Activist and former Democratic presidential candidate Jesse Jackson endorsed Sanders on Sunday. Jackson doesn't have the clout of Jim Clyburn these days, but he does still carry some weight. His endorsement may help Sanders.
But the Biden campaign also got an important endorsement. Senator Kamala Harris (D-California) endorsed him -- joining other former presidential candidates like Beto O'Rourke, Amy Klobuchar, Pete Buttigieg, and Michael Bloomberg.
Will the Jackson endorsement help Sanders make a comeback? Does the Harris endorsement effectively blunt that for Biden? We'll know tomorrow as several states vote. Sanders must do at least as well as he did in 2016, or he will fall too far behind to catch Biden.
NOTE -- I am an older white guy, and I do not support Sanders for the nomination. I voted for Warren in the Texas primary. But in 1984 and 1988, I was a Jesse Jackson delegate to the Texas State Democratic Convention, and I still have great respect for Mr. Jackson.