There was no other Democratic presidential candidate after the modern age who lent more enthusiasm than the 74-year-old former Delaware Sen. Joe Biden — at least, until Sen. Kamala Harris took the spotlight Tuesday.

It's not that there's anything unusual about the post-trauma grieving process. But it's the latest manifestation of the Joe Biden mystique, all but unmatched in presidential politics. Ask some voters who they're most excited about running, and they will probably mention Biden over Sen. Elizabeth Warren (D-Mass.), Bernie Sanders (I-Vt.) or Harris.

You hear it even among Republicans. Sen. Mark Kirk (R-Ill.) recently went to Delaware to meet Biden. Kirk had lost a fundraising battle to Harris last month and a poll in his state showed Biden taking more than two-thirds of the vote in the general election.

Some of that buzz may be self-satisfied relief at the idea of the man a little-known Republican once tried to have him thrown off the ticket.

Harris didn't help matters Tuesday with a nearly five-minute speech at the University of Michigan, playing up her feminist credentials and insulting Trump. But it is also undeniable that the enthusiasm is confined primarily to female voters, even as black voters see Biden as someone who could help them lift the mass black vote out of the election's back half.

In 2012, black turnout averaged 64% of the vote. (On Tuesday, according to preliminary exit polls, black turnout surged to 75% — or 7 percentage points higher than 2012.) Now, Democrats are targeting black voters, telling them that only they can attract a wider number of voters.

But some see Biden as an answer to that problem.

When he was the party's vice-presidential nominee in 2008, Biden didn't make a call to black voters in Pennsylvania, where John McCain had a historically good showing among that group. Biden didn't reach out to Latino voters. Neither did other possible 2016 candidates Hillary Clinton or Martin O'Malley. When President Obama was still largely unknown, he didn't bother.

Against Obama, Biden drew about 60% of the black vote in 2008. But for a quarter century, the press has covered Biden as a traveling preacher, taking advantage of local opportunities to explain that message of hope and change to black voters, and winning their support even as he never took a public stand on more polarizing issues.

This year, Hillary Clinton got an endorsement from Bethel AME Church, in an upstate New York city with a large population of black voters. But she did not endorse Biden.

In some ways, the Biden candidacy is a reaction to an Obama campaign that largely focused on black voters, including some of those who have mobilized in the protest movement of the last year. Biden's staff has made it clear that he is hoping to capitalize on the past willingness of black voters to be won over by the Democrat representing the black community.

If Biden can recreate the tremendous appeal of his 2008 campaign — or better — in 2016, the black vote could be critical to victory.

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