On Feb. 26, a poll of Virginia Democrats had Joe Biden at 19%, nine points behind rival Bernie Sanders. On March 3, Biden won Virginia with 53% of the vote.

On Feb. 23, a poll in Minnesota had Biden at 8%. On March 3, he won the state with 39% of the vote.

On Feb. 28, a poll in Massachusetts had Biden at 9%. On March 3, he won the state with 34% of the vote.

On March 2, a poll in Maine had Bernie Sanders beating Biden 43%-24%. The next day Maine Democrats voted and Biden won 34%-33%.

Simply put, Joe Biden pulled off one of the most dramatic and shocking political comebacks in the modern era. In the first three contests of the 2020 race for the Democratic nomination — Iowa, New Hampshire and Nevada — he trailed miserably to the victorious Bernie Sanders and his fundraising was so bad that he had little to no field offices or staff in the states cited above.

But on March 3, Biden won 10 contests to Sanders’ three, with California pending, and on March 10, Biden added more to that tally.

“Joementum” is not only real, but it should now take him all the way to the Democratic nomination. How did this political miracle happen?

South Carolina, and black voters, to the rescue: On Feb. 29, Biden didn’t just win the South Carolina primary, he dominated, beating Sanders 48%-20%. With Sanders leading in national polls before South Carolina, the margin of Biden’s victory shocked everyone.

It also made one thing very clear: Black voters are behind Biden in a big way. On March 3, exit polls showed black voters went with Biden over Sanders 55%-18%.

Quick decisions by his former rivals: Unlike the 2016 Republican primaries, where the non-Trump factions could never unite behind a single candidate, after South Carolina two of Biden’s rivals — Minnesota Sen. Amy Klobuchar and Iowa delegate winner Pete Buttigieg — dropped out of the race, endorsed Biden and immediately started campaigning for him.

Hours after endorsing Biden, Klobuchar had ads running in Minnesota, asking her supporters to vote for Biden. Another former rival, Beto O’Rourke, also endorsed Biden, helping him pull off an upset victory over Sanders in Texas.

The amazing aspect to all this was how quickly Klobuchar, Buttigieg and O’Rourke sprung into action after South Carolina, helping to form momentum that turned into a surge of votes for Biden on March 3.

Bernie Sanders’ weaknesses revealed: Bernie Sanders’ 2016 success in almost beating Hillary Clinton, and his three early 2020 victories, are notable and impressive. However, the rush of so many Democratic voters to Biden displays the fundamental flaws of his candidacy.

The first is a heavy reliance for his support on younger voters, who are often undependable in terms of actually showing up to vote. The second is his talk of revolution. Polls show that a majority of Democrats No. 1 priority is beating Donald Trump and are wary of overarching government programs such as “Medicare for All.” Many of Sanders’ policy proposals are indeed popular among primary voters, but Democrats worried that Sanders talk of revolution would make him vulnerable to Trump in the general election.

Going forward, there is little Sanders can do to stem the Biden surge.

The big question for the Democrats now is, what will Sanders and his supporters do? Will they throw up their hands in frustration and abandon the Democratic nominee and even the Democratic party?

Joe Biden has pulled off one political miracle. He may need a second one to get Bernie Sanders and his millions of fans to support him in the fall.

Bob Beatty is a political scientist in Topeka. He can be reached at bobbeatty1999@yahoo.com.