Vice President Mike Pence, center, Senator Kelly Loeffler, left, and Senator David Perdue, right, wave at individuals at Dobbins Air Reserve Base in Marietta, Ga., Friday, Nov. 20, 2020. Pence arrived on Friday to support Loeffler and Perdue, who are both facing a run-off election in January. (Alyssa Pointer /Atlanta Journal-Constitution via AP)

This story was updated on Friday, Nov. 20, 2020, at 4:22 p.m. with additional information.

CANTON, Ga. (AP) — Vice President Mike Pence campaigned with Georgia's two Republican senators Friday, trying to hold off their Democratic challengers in Jan. 5 runoffs that will determine who controls the Senate at the outset of President-elect Joe Biden's administration.

The trip highlights a critical juncture for the Republicans and Pence, who is trying to balance his own political future against his loyalties to a president who has yet to concede defeat.

Pence appeared with Sens. David Perdue and Kelly Loeffler on the outskirts of metro Atlanta's sprawling footprint, on the same day Georgia's Republican secretary of state was expected to certify that Biden is the first Democratic presidential nominee to carry the state since 1992.

Although Pence has joined President Donald Trump in not yet conceding to Biden, the vice president held fast Friday to more careful language than the president's repeated and baseless claims of widespread voter fraud.

"As our election contest continues, here in Georgia and in courts across the country, I'll make you a promise," Pence said. "We're going to keep fighting until every legal vote is counted. We're going to keep fighting until every illegal vote is thrown out. And whatever the outcome, we will never stop fighting to make America great again."

That position has grown increasingly fraught as more states certify election returns, and even federal judges appointed by Trump reject the president's specious claims of a fraudulent election. Pence, almost certainly a future presidential candidate himself, cannot yet afford to distance himself from Trump, but also must be careful not to attach himself to mistruths that undermine confidence in U.S. elections.

While Pence was on a bus tour in Georgia, a partial recount loomed in Wisconsin. Also Friday, the president called Michigan's Republican legislative leaders to a White House meeting, an extraordinary move that raises questions over whether the president is pressuring GOP state officials to select slates of electors to the Electoral College who might subvert the voters' will at the ballot box.

Pence focused Friday on securing the Republican Senate majority by helping Perdue and Loeffler defeat Democrats Jon Ossoff and Raphael Warnock, respectively. Having won 50 Senate seats in the new Congress, Republicans need one more for control. A Democratic sweep of the Georgia runoffs would yield a 50-50 Senate, giving Vice President-elect Kamala Harris the tie-breaking vote to tilt the chamber to Democrats.

With some irony, the Republicans' chief argument in the runoff contest has been to warn against giving Democrats complete control, a position that tacitly acknowledges that Biden will be sworn in as president on Jan. 20. Pence implied as much when he said Friday that a "Republican Senate majority could be the last line of defense for all that we've done."

Speaking before Pence, Perdue explicitly acknowledged Biden's win when he warned that if Georgia doesn't elect him and Loeffler, Democrats will "have the White House, the Senate and the House of Representatives. They'll do anything they want."

Perdue led Ossoff in the general election but narrowly missed the majority that Georgia law requires to win statewide elections. Warnock and Loeffler were the top finishers in an all-party special election to fill the final two years of former Sen. Johnny Isakson's term. Republican Gov. Brian Kemp appointed Loeffler to the post after Isakson announced his retirement last year.

Voters at the rally were in many cases more focused on Trump than the senators, chanting "Four more years" and "Stop the steal."

"I'm here to see Pence because I support Trump," said John Weaver, a 46-year-old Ellijay resident who said he believes Trump won.

Loeffler devoted part of her speech to attacking Warnock, echoing recent television advertising by calling him a "radical's radical."

"We are the battleground," she said. "We are on the front line defending the majority, but we're also the firewall against socialism in this country."

Neither Warnock nor Ossoff are socialist, but Republicans believe the inaccurate labeling is the best way to encourage conservative Georgians to cast runoff ballots and perhaps to coax support from GOP-leaning voters, especially in the Atlanta suburbs and exurbs, who backed Biden because of their distaste for Trump.

Pence first spoke in Canton before a second rally in Gainesville, also north of Atlanta. The exurban venues underscore Republican math in Georgia: both are in heavily Republicans counties growing fast.

Atlanta's closer-in suburbs have flipped to Democrats, who have moved into the exurbs as well. To win these runoffs, Republicans must maximize their remaining advantages in the exurban ring in the same way that Democrats must wring every vote from Atlanta and nearer suburbs.