Donald Trump has railed against Georgia's voting system, berated elected GOP officials and sowed doubt over the November election with unsubstantiated claims of voter fraud. But on Saturday, the outgoing president will ask his loyal base to put aside any fears and mistrust they may have in the system and vote in the Jan. 5 runoff elections to keep Republicans in the Senate majority.

In his first public campaign appearance since the Nov. 3 election, Trump will travel to Georgia to boost a number of GOP candidates, namely Sen. Kelly Loeffler and Sen. David Perdue, who are locked in competitive runoffs. Republicans must win at least one of the runoffs to maintain narrow control of the Senate and block Democrats from gaining unified government – the presidency and both chambers of Congress – for the first time in a decade.

His active involvement is seen as a double-edged sword. Trump, who is reportedly weighing a comeback bid in 2024, is arguably the only Republican politician who can generate the excitement needed among base voters who are even more critical this time around in a lower turnout election. But Trump also threatens to re-energize Democrats who voted against him last month. And with his incessant claims about fraud, his rhetoric could indirectly depress GOP turnout if voters decide to sit this election out and threaten the Republican majority.

"If the rally is focused on, 'This is why you should elect Perdue and Loeffler and why you need to turn out to vote,' I think that could be incredibly helpful for the race," says Amy Steigerwalt, a political science professor at Georgia State University.

"If, however, the rally is more focused on allegations of fraud or illegal actions or bashing Republican elected leaders of the state, I think that that is perhaps going to backfire and could really make it more difficult to convince voters on the ground what it is they're supposed to do and what they're fighting for," she adds.

Trump and his allies have been sending Georgians mixed signals about voting. They continue to contest the results of the election that propelled President-elect Joe Biden to victory, all while asking voters to once again return to the polls and send Loeffler and Perdue back to Congress.

Plus, some pro-Trump allies are complicating Republicans' work to mobilize voters for the runoffs. Two lawyers, Lin Wood and Sidney Powell, reportedly encouraged Georgians not to participate until their votes are "secure." Powell, however, is no longer affiliated with Trump's legal team. Their rhetoric has sparked the ire of Republicans who believe it's counterproductive to their efforts.

"Lin Wood and Sidney Powell are totally destructive," former House Speaker Newt Gingrich of Georgia tweeted Thursday. "Every Georgia conservative who cares about America MUST vote in the runoff. Their dont vote strategy will cripple America."

In November, Biden narrowly won Georgia and delivered Democrats their first win in the state at the presidential level since 1992. In that same election, candidates in both Senate races were unable to clinch the 50% needed to avert runoffs. But even after Biden's victory, Democrats still have an uphill fight in January since more votes were cast for Republicans on Nov. 3. Plus, Republicans have a longer history of prevailing in runoff elections in Georgia.

The effectiveness of Trump's rally, political observers say, will all come down to his messaging. Even if Trump steers the focus away from Loeffler and Perdue and focuses on himself, it could still be beneficial to them since he'll be addressing avid supporters who backed his agenda for the past four years. But if he veers into the territory of alleged voter fraud and abuse, that could be more damaging to the GOP's runoff prospects.

"The emphasis is going to be on him," Steigerwalt says. "Perhaps though, maybe that will do less potential harm to their ability to get out the message they need to get out. Even if he keeps the emphasis on him but suggests (Loeffler and Perdue) have supported him all along, that would be helpful."

Trump's tweets and legal posturing ahead of Saturday's rally give a preview of how he might weave in his voting issues into the Senate runoffs. He continued raising concerns with the November presidential election, specifically calling out the two Republican state officials he's targeted for weeks – Gov. Braian Kemp and Secretary of State Brad Raffensperger. And on Friday, Trump's campaign filed a lawsuit in state court seeking to invalidate Georgia's results. The lawsuit comes as the state winds down its recount and re-certifies the vote.

"The 'Republican' Governor of Georgia, @BrianKempGA, and the Secretary of State, MUST immediately allow a signature verification match on the Presidential Election," Trump tweeted this week. "If that happens, we quickly and easily win the State and importantly, pave the way for a big David and Kelly WIN!"

But the president's consistent bashing of Kemp, Raffensperger and other local officials has caused a rift among the Georgia GOP that has spilled out into the public. Earlier this week, Gabriel Sterling, Georgia's voting system implementation manager – and a Republican – angrily called out Trump and both Republican senators for refusing to condemn violent threats that have been levied at elections officials.

The argument for Republicans in the runoff is a harder needle to thread when Trump – and many in the party – haven't acknowledged his loss. During Vice President Mike Pence's trip to the state last month, he made a subtle reference to Biden's victory by arguing for the importance of keeping a GOP majority as a "last line of defense for all we have done.".

Democrats, meanwhile, are seeking to get a boost from former President Barack Obama, who held a virtual event Friday on behalf of Georgia candidates Jon Ossoff and Raphael Warnock. Ossoff is running against Perdue, while Warnock is challenging Loeffler for the final two years of former GOP Sen. Johnny Isakson's term.

Until Friday, Democrats relied much less on national leaders for the runoffs than Republicans. Stacey Abrams, a former state legislator and 2018 gubernatorial nominee, is once again playing a big role in Georgia after successfully mobilizing her voter organization in November.

While Democrats are keeping some distance from Washington, the former president remains a highly popular figure in the party and played a critical role in elevating Biden during the November election. Biden affirmed Friday after a speech in Delaware that he will visit Georgia, though he didn't indicate when he'd make the trip.

Alongside Warnock and Ossoff virtually, Obama urged Georgians to repeat the large turnout from November, leaning on his own experience in the White House when his agenda faced major roadblocks from a McConnell-led Senate majority.

Black voters, specifically, played a pivotal role in delivering the state to Biden last month. Democrats will once again rely on higher turnout in and around Atlanta. If Warnock wins the special election, he will become the first Black senator to represent Georgia.

"The Senate is a place where, even with a big majority, it's tough to get legislation through. And if you don't have a majority … they can block just about anything," Obama said Friday. "You are now once again the center of our civic universe because the election in Georgia is going to determine ultimately the course of the Biden presidency and whether Joe Biden and (Vice President-elect) Kamala Harris can deliver legislatively all the commitments they've made."