It is time for progressive Democrats to prepare for the possibility of a Joe Biden presidency — and for that presidency to last just four short years.

Why? Because that's apparently is what Biden himself is doing. Politico on Wednesday reported the former vice president is "quietly" signalling to aides he would serve only a single term, if elected, in part to mollify young lefty voters who seem unenthusiastic about his campaign.

"If Biden is elected, he's going to be 82 years old in four years and he won't be running for re-election," an unidentified campaign adviser said.

Biden denied the story, but a denial would be expected. And there is a precedent for such a move — Rep. Nancy Pelosi (D-Calif.) won the House speakership earlier this year based, in part, on a pledge to give up the post no later than 2022. It seems the septuagenarians who make up the leadership of the Democratic Party are taking an Augustinian approach to passing the torch to the next generation: They're willing to do it, but not just yet.

It could work. Biden has been at or near the top of the Democratic polls since entering the race, and he has continued to poll solidly among the African-American voters who are a critical part of the party's base. The party's leftmost activists find Biden endlessly frustrating — with good reason — but right now there is a pretty good chance he will be the party's nominee next fall.

Anything could happen, of course. But progressives should start preparing for the opportunity that a single-term Biden presidency might offer them.

First, they should realize that the campaign for the vice presidential nomination begins … now. The person who claims the nomination will have a leg up on winning the party's presidential nomination, and perhaps the presidency itself, in 2024. So Democrats with an eye on the long game should already be thinking hard about who they want to be the veep nominee.

The exit of Sen. Kamala Harris (D-Calif.) from the race has generated angst in the party about the whiteness of the remaining leading candidates. It has been 16 years since the party last offered voters a ticket with two white men on it; 2020 will not be the year Democrats go back to the old ways of doing things. So the ideal candidate to join Biden will be somebody young, progressive, and very likely a woman of color. Stacey Abrams, the former gubernatorial candidate from Georgia, fits the bill — and she would be available.

Second, Democrats must remember that effective governing requires more than winning the presidency — it will take winning Congress, as well. Democrats appear to have good odds of retaining their majority in the House of Representatives, and they have a shot at winning the Senate. The focus on the presidency, though, has meant that Dems have been slow to put their best people forward for the Senate. A better, concerted effort will be needed — or else a Democratic president in 2021 will be hobbled by Sen. Mitch McConnell (R-Ky.) and company.

Which leads to the third point: Progressives may not like Biden all that much, but they should do more than hold their noses and vote for him — they should work vigorously for his victory. That should be obvious, given the massive and justified discontent with President Trump.

But voters of a certain generation will never forget how discontented progressives in 2000 fled the Democratic Party and its nominee, Al Gore — an unexciting, imperfect moderate — to vote for Ralph Nader, thus helping George W. Bush narrowly win the presidency. And it has been only four years since some supporters of Sen. Bernie Sanders (I-Vt.) revolted against Hillary Clinton's nomination — though Sanders himself campaigned respectably for her that fall.

There is still time for this year's progressives to campaign for Sanders or Sen. Elizabeth Warren (D-Mass.), of course. But if Biden does win the nomination, there will be no time for petulant, third-party rebellion. Trump is that bad. Biden might not offer the agenda aggressiveness the party's left-wing desires, but this shouldn't be a close call. A Bidenesque half-loaf is far superior to the dystopian nothing Trump has to offer them.

Besides, if they play it right, a single-term Biden presidency might offer progressives a platform for long-term electoral and policy success. The opportunity is there. The time to start seizing is now.

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