ATLANTA — Debate over President Trump's own electoral grievances dominated the final day of campaigning for two U.S. Senate runoffs in Georgia on Monday, raising concerns among Republican strategists and local officials that his conspiracy theories would depress GOP turnout and jeopardize continued Senate control.

The Republican secretary of state’s office on Monday held a news conference with a top election official to denounce Trump’s false claims of election fraud over the weekend, urging Georgians to “please turn out and vote tomorrow.” At an earlier event in Milner, Ga., Vice President Pence was interrupted by someone who shouted a demand that Pence overturn the presidential election results.

President-elect Joe Biden, who also traveled to the state on Monday, turned Trump’s efforts to overturn the November election results into a rallying cry to drive Democrats to the polls on Tuesday. Only by winning both seats would Democrats control the Senate, giving Biden far better odds of pushing through his agenda.

“In America, as our opposition friends are finding out, all power flows from the people,” Biden said at an Atlanta rally, in a reference to Trump’s attempts — unsuccessful so far — to force the courts or state officials to overturn the results. “Politicians cannot assert, seize or take power. Power is granted by the American people and we cannot give that up.”

Little about the first campaign clash of 2021 suggested a fresh political start for the new year. The president’s nine-week effort to reverse the November vote, which he hopes will come to a head Wednesday when the House and Senate meet to accept those results, have become the biggest applause lines at Republican events in the state, popping up even when party leaders wanted to focus on issues closer to home.

President Trump’s rally for Sen. Kelly Loeffler and former senator David Perdue in Dalton, Ga., on Jan. 4 was riddled with false or misleading claims. (The Washington Post)

As a result, Republican strategists spent much of Monday focused on pressuring Trump and his aides to script his Monday night appearance in the state in a way that does not further undermine their chances.

“It is a white-knuckle moment for Republicans all over the place,” said one strategist who spoke on the condition of anonymity to be frank. “He wants attention more than he wants the win, and that could really screw us. So much of these elections are about momentum.”

Trump ultimately gave both Republican candidates in the Georgia runoffs, Sen. Kelly Loeffler and David Perdue, ringing endorsements during a rally in Dalton, Ga., calling them the “last line of defense” against Democratic control of the Senate.

“Tomorrow, each of you is going to vote in one of the most important runoff elections,” he told the crowd, before embracing both without reservation. “Kelly fights for me, David fights for me — that I can tell you.”

But Trump also doubled down on his unfounded claims of fraud in the presidential election. He pressured Pence to push to overturn the election results on Wednesday and promised to campaign against Georgia Gov. Brian Kemp, whom he previously supported, and Georgia Secretary of State Brad Raffensperger.

President Trump on Jan. 4 said he hopes Vice President Pence, who oversees the certification of the Electoral College vote, will "come through for us." (The Washington Post)

“They say they are Republicans. I really don’t think they are,” said Trump, who has relentlessly criticized them since Biden was declared the winner in Georgia.

Democratic strategists also expected Trump to play a decisive role in the outcome.

“All of the story is about their turnout,” said J.B. Poersch, the president of the Senate Majority PAC, the largest outside group supporting Democrats in the state. “If they win it is because they had enough enthusiasm to go to the polls. And if they lose it is because there was a lot of ambivalence.”

Widely circulated false conspiracy theories have animated Republican crowds on the campaign trail in the closing days. At the final public rallies for Loeffler, her loudest applause came not when discussing her background in business, or the “radical liberal” agendas of the Democrats, but when discussing Republican challenges to the Nov. 3 vote.

“We have to get to the bottom of these elections,” Loeffler said at a Sunday night rally in Cherokee County, one of the Republican strongholds where the party is trying to boost turnout. “The Democrats will never look into this. That’s what we’re fighting for, integrity in this country.”

But she also was concerned that the focus on the last election could divide her own voters. She had refused as the runoff date neared to take a clear position on whether she would support Trump’s efforts to get the Senate to refuse the electoral college result later this week, although she announced in a statement Monday evening and again at the rally that she would back the president. Asked on Saturday about the challenge to the electoral college that Trump has backed, she had offered a vague comment. “Everything is on the table,” she said, before returning to a familiar line.

Perdue, whose Senate term lapsed on Sunday, leaving him on the sidelines for the electoral college fight in that chamber, has said he would support the effort to challenge the election result.

“They stole the election. That’s the truth. We’ve got tons of evidence,” said Patty Smith, 61, who interrupted Pence during his event by shouting for him to “do the right thing on Jan. 6,” when Congress will meet to accept the election results.

Republicans have not submitted credible evidence of widespread fraud, but the sentiment was widespread enough that local Republican officials held the news conference to contest, point by point, the case Trump argued in a phone call over the weekend with state officials that the election result was wrong.

“This is all easily, provably false,” Gabriel Sterling, a Republican official who oversaw the voting systems in the state, said at the news conference. “Yet the president persists and by doing so undermines Georgians’ faith in the electoral system, especially Republican Georgians, which is important because we have a big election coming up.”

When they could, both Perdue and Loeffler focused on a unified message that blanketed the state’s airwaves: Only their election would save the nation from the socialist decline they said would result from victory for their rivals, filmmaker Jon Ossoff and the Rev. Raphael Warnock., who both reject the “socialist” label.

“The very future of our republic is on the line,” Perdue said at the Pence rally, addressing the crowd by telephone because of a coronavirus exposure that has put him in quarantine. He said the result could set the country’s course for “at least 50 to 100 years.”

The Democratic candidates spent the closing days of the race trying to refocus the campaign on more local concerns such as health care and jobs, even as they brought in star power to help seal the deal and continued to jab at Trump. A closing ad for Ossoff featured narration by former president Barack Obama and a musical appearance by John Legend.

“When the president of the United States calls up Georgia election officials and tries to intimidate them to change the election results . . . that is a direct attack on our democracy,” Ossoff said in Savannah on Sunday, at an event with Vice President-elect Kamala D. Harris. “And if David Perdue and Kelly Loeffler had one piece of steel in their spine, one piece of integrity, they would be out defending Georgia voters from that assault.”

Warnock, speaking at a Monday afternoon rally in Clayton County, ridiculed Trump for his appeal to state election officials to reverse the presidential results — especially “in the middle of a pandemic” — but told his own supporters to “pay him no mind.”

“The only way this thing goes in the wrong direction is if we become overly confident and give in to the ghosts of complacency and indifference,” Warnock said. “We lose only by the margin of our disengagement.”

Democrats, who have long considered themselves underdogs in the runoff contests, have been cheered by early vote numbers and clear signs in the state that many core Democratic constituencies, including suburban and urban voters, remained engaged. Public polling, which has been less prominent than during the presidential campaign, has generally shown a close race.

Just about every available bit of television and radio airtime has been consumed by the four campaigns and their supporting outside groups, leading to a barrage of messaging. But Democrats thought their advantage came via an aggressive voter registration effort, which continued after the presidential campaign, and a large get-out-the-vote operation that did not pause after Biden’s victory.

“Over the course of this campaign, it is clear that the structural advantages that we had, the sweat equity on the ground, has paid off,” said Bradley Beychok the president of American Bridge, a PAC that has spent about $9 million to elect the two Democrats. “A day out, it is clear that this race is a toss-up and we maybe have a slight advantage.”

The Republican candidates have been bedeviled by Trump’s actions, even as the president remains one of their biggest assets. Both Perdue and Loeffler have said they support Trump’s late call for $2,000 stimulus checks to Americans, a move that is also backed by House Speaker Nancy Pelosi (D-Calif.) and opposed by Senate Majority Leader Mitch McConnell (R-Ky.).

But the debate over whether to approve larger checks for American workers gave their Democratic opponents an opportunity to seize on the issue, arguing that the best way to secure increased payments is by giving Democrats control of both chambers.

“The debate over $2,000 isn’t about some abstract debate in Washington. It’s about real lives, your lives, the lives of good hard-working Americans,” Biden said in Atlanta on Monday. “If you send Jon and the reverend to Washington, those $2,000 checks will go out the door.”

On other recent Trump maneuvers, the Republican candidates have been less clear, as they try to minimize divides in their own party. Besides brushing aside questions about Trump’s efforts to overturn the electoral college results, Loeffler has declined to take a firm position on whether she would have voted to override Trump’s veto of the defense authorization bill, after missing the vote in December.

Even as Democrats have been bolstered by the high numbers of early voters, particularly in liberal-leaning areas where they have focused their efforts, many note that the gains come against a historical conservative lean of the state.

“If you look at these numbers, you will see White and Black voters are voting at slightly higher rates,” said Michael Thurmond, the chief executive of DeKalb County and the first African American in modern Georgia history to win a statewide election (labor commissioner) without first being appointed to an office. “But about 70 to 75 percent of White voters are Republicans, and Republicans vote in higher numbers on Election Day, so it’s too early to draw any conclusions.”

Thurmond also said the historic nature of the pair of Senate runoffs has Democrats not wanting to celebrate too early. The high stakes have meant heavy attention and big money in Georgia. The national stakes of the races mean they have seen unprecedented attention, and nearly half a billion dollars in campaign cash was expected to flow into Georgia during the two months of the runoffs.

Georgia election officials, who have been beating back unfounded claims of fraud and malfeasance since November, say they’re ready for attention once again as part of the runoffs.

“All the counties in Georgia are in the spotlight right now, so we are all prepared for this as well as we can be,” Richard Barron, Fulton County’s elections director, said at a news conference Monday afternoon.

Trump has attacked Fulton County repeatedly since he lost the state — including in his weekend call to the secretary of state and others. Barron said his staff has had to endure threats and slurs a bomb threat, multiple death threats and racial slurs in the run-up to Tuesday’s vote.

“We’re trying to take each of those things as they happen and just continue to do our jobs,” Barron said.

Mike DeBonis and Anne Gearan contributed to this report.