Trump's false fraud claims could threaten GOP hopes in Georgia Senate races

A day after posting a 46-minute diatribe filled with falsehoods about the election he lost, President Donald Trump on Thursday continued to baselessly dispute the outcome.

It could be a preview of his first big political rally since being defeated -- when he campaigns Saturday in Georgia where runoff races will determine if the GOP can keep control of the Senate.

"It's massive fraud," he told reporters in the Oval Office, echoing his display in the video, "probably the most fraudulent election that anyone has ever seen."

On Wednesday, standing at a podium with the presidential seal, in the White House -- he unloaded a dizzying array of false claims about electoral fraud that amounted to a verbal assault on democracy.

Posted on Facebook, along with a condensed version on Twitter -- on which the social media platform quickly slapped a "disputed" label -- Trump called it maybe "the most important speech I've ever made." But it amounted mostly to a formal recitation of his tweets and retweets of the past month, in which he increasingly clung to debunked conspiracy theories to argue that he won the election.

Trump planned to travel to Georgia to speak at what has been billed as a "victory rally" for the two GOP senators competing in the runoffs – an attempt to sway voters and show he still commands considerable political influence.

But fellow Republicans worry if he keeps calling the voting system in the state illegitimate -- it could backfire by hurting GOP turnout.

Sen. Roy Blunt, R-Mo., said Monday that what Trump says during his visit to the state "will probably matter more than what he has said up until now."

"I think it will help if the president goes and encourages turnout," Blunt said. "But I'm not very concerned about what others might be saying."

At a rally in Georgia Wednesday, Trump ally Sidney Powell -- until recently a member of the campaign's legal team -- told Georgians to make clear they would "not vote until you know your votes are secure."

Democrats are currently slated to hold 48 seats in the next Senate, and winning both run-offs could give them as many as Republicans -- with Vice President-elect Kamala Harris, a Democrat, casting tie-breaking votes.

Georgia has typically sent Republicans to the Senate in recent history, but Democrats hope changing demographics will help them win an uphill battle. Former Vice President Joe Biden carried the state in the presidential vote last month.

While small cracks have emerged in national GOP support for Trump's quixotic endeavor, most Republican senators have held the president’s line in refusing to recognize Biden as the president-elect, despite his winning the election.

On Wednesday evening, through, one of Trump's closest allies in the Senate, Sen. Lindsey Graham, R-S.C., addressed Trump's legal team during an interview with Fox News. "Doing a video is not proof," he said.

Despite the COVID-19 pandemic ravaging the country -- killing thousands of Americans -- Trump said in an interview with Fox News on Sunday that he would spend "125% of my energy" focused on proving fraud occurred. Courts and electoral bodies have over the past month repeatedly rejected such charges from his lawyers and allies.

Asked Thursday what, if anything, the president was doing that day to address the pandemic as he pursued his political claims, the White House did not offer any specifics.

"President Trump is briefed on the pandemic regularly and the Trump administration continues working around the clock to save lives and fight the coronavirus," White House deputy spokesman Brian Morgenstern said, although he declined to say if the president was briefed Thursday.

Rather than devote significant time to the surging virus, the president has instead held events at the White House that directly contradict federal guidance on how to slow its spread.

This week, he attended an indoor holiday reception with little mask-wearing or social distancing and hosted dozens of people in the Oval Office for a medal ceremony.

His Saturday rally appears to be styled after the dozens he held in the final days of his re-election campaign, when thousands of his supporters crammed together -- typical outdoors on airport tarmacs -- with most of the crowds typically not covering their faces.

The president has also in recent days turned his ire about alleged election fraud toward Attorney General Bill Barr, who on Tuesday told the Associated Press that the Department of Justice had not uncovered evidence of widespread voter fraud that would change the election results.

Trump met with Barr after the interview was published, according to multiple sources familiar with the matter. One source briefed on the meeting described the interaction as "intense."

Asked Thursday if he still had confidence in the attorney general, he demurred.

“Ask me that in a number of weeks from now," he told a reporters, after saying Barr should look into baseless allegations of voting fraud in Georgia, where Trump is headed this weekend.

ABC News' Allison Pecorin, Katherine Faulders, Alexander Mallin, Will Steakin and Olivia Rubin contributed to this report.