Why Obama still matters to both Biden and Trump
It's a classic political moment -- the still-popular former president hitting the trail for his loyal former deputy, helping to close strong for the man he wants to see continue his legacy.
But even if former President Barack Obama was filling a stadium as opposed to its parking lot on Wednesday, this would not be a moment for nostalgia among Democrats.
As Obama makes his first in-person campaign visit on behalf of Biden on Wednesday in Philadelphia, it's worth remembering how vital the former president is to the political identity of both Biden and Trump.
Obama has been an omnipresent force this campaign, if often slightly off-stage. Biden's references to "Barack and I" helped carry him through primaries where Obama stayed neutral, and Trump's rants about "Obamagate" and other exaggerated alleged transgressions are part of his greatest-hits rally rotation.
Obama on Wednesday is expected to emphasize down-ballot races and speak directly to Black men, amid signs that Biden is underperforming in that demographic. Younger Black voters in particular are a concern for the Biden campaign, which sees potential victory in turnout in Philadelphia, Detroit and Milwaukee -- to say nothing of Charlotte, North Carolina, and Atlanta.
A "drive-in car rally" with honks and high beams do not make the visuals anyone could have predicted for Obama's return to the trail.
But the former president is a potent political force -- something both Biden and Trump can agree on.
-ABC News’ Political Director Rick Klein