Joe Biden campaign deploys top surrogates while candidate preps for final debate

As former Vice President Joe Biden stays off the campaign trail in the days leading up to Thursday's final presidential debate, a stable of surrogates spanning the ideological spectrum of the Democratic Party has been crisscrossing the country to get the nominee's message out in the race's final days.

Biden's absence on the trail ahead of his final debate clash with President Donald Trump has drawn criticism from Republicans, who have sought to cast the nominee as "hiding in his basement." But it also gives Democrats a chance to highlight an array of voices who could help them juice turnout in key battleground states in the waning days of the campaign.

One of those key figures, former President Barack Obama, is set to make his first in-person campaign appearance on behalf of Biden this cycle at a drive-in event in Philadelphia on Wednesday, an appearance where he is expected to highlight the historic stakes of this election and emphasize the urgency of voting early. He will also discuss the importance of down-ballot races, according to an Obama aide.

A consistent presence on the campaign trail this month has come from a duo that likely knows the Democratic ticket better than anyone -- the candidate's spouses.

Biden's wife, Dr. Jill Biden, has headlined roughly 25 events in eight battleground states in October -- including Florida, Georgia and Texas -- in addition to a steady flow of virtual events. Douglas Emhoff, Harris' husband, has also hit a diverse slate of over a dozen battleground states this month, with many events centered around early voting.

Biden himself has visited eight different battleground states in October, including multiple visits to Florida, Michigan and Pennsylvania -- three states pivotal to his chances of defeating Trump.

Several of Biden's former Democratic rivals have also hit the trail to stump for the ticket, with Sen. Elizabeth Warren, D-Mass., Sen. Bernie Sanders, I-Vt., Andrew Yang and Pete Buttigieg holding events across battlegrounds states on behalf of Biden and Harris.

"I think there's a lot of folks who have voted Republican their whole lives, out of habit if nothing else, who are starting to say, 'Wait a minute, this isn't me,'" Buttigieg said during a campaign stop in Stockbridge, Michigan, on Monday, hoping to peel off GOP voters.

The strategy, some Democrats say, is one way to reinforce the idea of a united front in the final days of a bruising campaign that has seen the Republican incumbent seek to create cracks in Biden's coalition.

"They are role-modeling a vision of unity and bringing all voices to the table. It is also a very strong contrast to Trump, who has not grown his base in any way. In addition, this strategy makes it difficult for a Trump to split the Democratic base that Biden has built," Amanda Renteria, the national political director for Hillary Clinton's 2016 campaign, told ABC News.

"Momentum is the driving factor at this point. [Surrogates] will be in every key district and keep the energy up as lines continue to form. This year is also an important year because people have so many unusual pressures on them, so the extra energy, support, headlines and events are even more critical," Renteria added.

In the days leading up to the debate, Biden's team of surrogates have zeroed in on the make-or-break Rust Belt states of the Midwest, with both Jill Biden and Buttigieg making trips to Michigan ahead of the debate, and Sanders expected to join the list of surrogates stumping in Pennsylvania on Sunday.

Out on the trail amid the COVID-19 pandemic, Biden and his long list of surrogates have had the additional challenge to connect with voters in the key state in a socially distanced manner. The campaign has largely turned to drive-in rallies to replicate the traditional campaign trail feel following their success with the model during the final night of the Democratic National Convention in August.

Biden campaign aides point to the COVID-safe rallies, which often feature cars decorated with signs of support for the Democratic ticket and rounds of honks rather than applause from invite-only crowds, as an energetic boost for the campaign that for months existed in an exclusively virtual state.

Still, the Biden campaign has continued to find success in some virtual aspects of the campaign, getting a boost from famous faces in virtual fundraising.

In the week before the debate, the campaign hosted a virtual grassroots fundraiser with the cast of the hit musical "Hamilton" -- the best-attended fundraiser to date with 120,000 participants -- and assembled portions of the "Avengers" cast Tuesday for a Q&A event with Harris.

All told, the Biden Victory fund is expected to hold 41 virtual fundraisers before Oct. 30 with a host of surrogates, including Clinton, Justin Timberlake, Cindy McCain and David Letterman.