Georgia’s Senate run-off elections arrive Tuesday after a whirlwind two-month campaign that smashed fundraising records, inspired historic voter turnout, bombarded the airwaves with ads, and loomed over congressional negotiations on major spending legislation.

The stakes may never have been higher in such a narrow election. Amid President Trump’s incessant attacks on Georgia’s election integrity, four people are seeking two seats that will determine which party controls the Senate. For President-elect Joe Biden, nothing less than his entire agenda is on the table.

Those high stakes are underscored by planned visits on Monday by Trump and Biden, repeat appearances for both the outgoing and incoming presidents.

“Something like this has never happened before and probably never will again,” said University of Georgia political scientist Charles Bullock. “Two seats, from one state, in one election, that will decide Senate control. It’s just unprecedented.”

President-elect Joe Biden speaks at a drive-in rally Dec. 15 for Georgia Democratic candidates for U.S. Senate Raphael Warnock and Jon Ossoff in Atlanta. Patrick Semansky/Associated Press

During the final week of the campaign, the events ranged from small, tightly controlled get-togethers to drive-in rallies. Voters said they understood the broader significance of these races – and the circumstances surrounding them.

Democrat Terri Sapp, 47, said she voted early “because I just didn’t want to risk the chance that something might happen to me first,” and to “fire” Republican Mitch McConnell as Senate majority leader.

Trump has focused his attention in the state not on the Republican candidates or the future of the Senate, but almost entirely on his baseless claims that voter fraud caused Biden to win the state in November by a little more than 12,000 votes. Some Republicans fear he may throw the election to the Democrats by demanding the resignation of Governor Brian Kemp and Secretary of State Brad Raffensperger, both Republicans.

If Democrat Jon Ossoff can beat first-term GOP Senator David Perdue, and fellow Democrat Raphael Warnock can defeat Republican Senator Kelly Loeffler, the Senate will be split 50-50 between the parties. If that happens, Vice President-elect Kamala Harris would cast any tie-breaking vote, effectively flipping control of the chamber to Democrats.

But a victory by either Republican would give McConnell 51 votes, a slim majority but enough to curtail Biden’s initiatives and block key nominations to his cabinet and the judiciary.

Democratic U.S. Senate challenger the Rev. Raphael Warnock during a rally, Dec. 21 in Columbus, Ga. with Vice President-Elect Kamala Harris and fellow Democratic U.S. Senate challenger Jon Ossoff. Ben Gray/Associated Press

Perdue’s chance for last-minute barnstorming was curtailed after he decided to quarantine after coming into close contact with someone who tested positive for coronavirus, meaning he’ll likely skip Trump’s Monday rally and his own event on election night.

Limited polling in the state shows both races are extremely close while drawing intense interest. More than 70,000 new voters have registered in Georgia since Nov. 3. More than 2.8 million people had cast ballots as of Thursday, shattering the previous record for the December 2008 Senate runoff, when 2.1 million votes were cast.

Although Georgia doesn’t register voters by party, the locations of heavy early voting in urban and minority areas suggests strong Democratic turnout. But Republicans tend to vote in person on Election Day so it’s difficult to predict an outcome.

The results won’t be known for days, given that it took 10 days to call the Nov. 3 election in Georgia. And those counts will almost certainly face legal challenges.

The unusual dual run-offs are playing out because none of the candidates got more than 50 percent of the vote in the Nov. 3 general election, a requirement for winning statewide elections in Georgia.

Since then, spending has poured in for the twin contests, which the Center for Responsive Politics now lists as the two most expensive congressional elections in American political history. Nearly half a billion dollars has been spent just in the runoffs, with another $205 million spent during the first round.

Democratic nominee for U.S. Senate from Georgia Jon Ossoff speaks after voting early in Atlanta on Dec. 22. John Bazemore/Associated Press

Georgians last elected a Democrat to the Senate two decades ago, and such runoffs in the state typically have low turnout, which favors Republicans. Yet Democrats are fighting hard after Biden took the state. High-profile Democrats, including former first lady Michelle Obama, have cut ads on their behalf.

“The state is clearly going through some realignment,” Bullock said. Bill Clinton in 1992 was the last Democratic president to carry Georgia before Biden, and a Democrat hasn’t held a Georgia Senate seat since 2005.

In their campaign-trail messaging, Republicans Perdue and Loeffler claim Ossoff and Warnock are “dangerous radicals” and socialists who’ll support liberals like New York Representative Alexandria Ocasio-Cortez and House Speaker Nancy Pelosi. Warnock is under attack for past supportive statements about the late Cuban dictator Fidel Castro, Nation of Islam leader Louis Farrakhan, and the pastor Jeremiah Wright, whose sermon including a condemnation of the U.S. was a campaign flashpoint for Barack Obama in 2008. Ossoff, educated at Georgetown University and the London School of Economics, has been dismissed as a “trust-fund socialist.”

From the left, Ossoff and Warnock claim the Republicans are heartless and too wealthy to relate to or care about the less fortunate – Loeffler’s husband Jeff Sprecher, chairman of the New York Stock Exchange, recently hit the billion-dollar mark – and who tried to enrich themselves at the expense of Georgia residents suffering from the coronavirus pandemic and the resulting economic downturn.

Democratic state Rep. Roger Bruce, 67, said his party is benefiting from an influx of more diverse voters in the fast-growing suburbs around Atlanta, and Black voters inspired by what he called “big time” racial overtones in Republicans’ rhetoric.

A photo of Loeffler posing beside a former Ku Klux Klan leader – she says she was unaware of his affiliation – bolstered those perceptions, said Bruce, along with her earlier criticisms of the Black Lives Matter movement. Those remarks prompted some members of the Atlanta Dream WNBA basketball team, which Loeffler co-owns, to wear “Vote Warnock” T-shirts.

“The reality is we’ve already shown that we can get more votes than them. Donald Trump got less votes. We just got to do it again,” Bruce said.

Ossoff on Tuesday repeated the claim that Perdue “has been personally profiting from this pandemic.” Investigations into stock sales by both Perdue and Loeffler that occurred after Congress was briefed on the coming pandemic before the public was fully aware haven’t led to any ethics citations or other charges.

Despite being caught awkwardly between supporting Trump’s claims of voter fraud and their need to spur GOP turnout, both Republicans have underscored continued allegiance to the president, including siding with him against McConnell on increasing stimulus payments in the virus relief package from $600 to $2,000, a sideshow from Washington during the runoffs.

Perdue boasted to supporters in the Atlanta suburbs how he consulted with the president over Christmas about the new stimulus package, before Trump signed it, and reminded them that the president will return for a second rally for him and Loeffler on Monday.

“Let’s not let them slip in here in a runoff just because the president is not on the ballot,” Perdue said of the Democratic candidates.

Loeffler used similar rhetoric at an event in Columbus.

“This is why we have to hold the line. This is why we’re the firewall. This is why we cannot let Chuck Schumer’s radical agent of change – Raphael Warnock – and his running mate, the trust-fund socialist Jon Ossoff, into the Senate. Because they radically want to change America,” Loeffler said, referring to the Senate minority leader.

Many of those interviewed at Loeffler and Perdue campaign events said they’ve been influenced by ads linking Warnock and Ossoff with images of liberal politicians from the coasts.

“He’s way too radical for me,” former State Representative Gary Cason, 77, said of Warnock. “In every which way you can think of,” added Herman Dowden, 70, of Ellenwood.

“I think that when we paint pictures of people as radicals, and as not in touch with society, it is not a good strategy,” said Olu Brown, 43, pastor of Impact Church in Atlanta, who backs the Democrats. “This is an opportunity to really focus on Georgia and what’s good for Georgians – and I think Warnock and Ossoff have done that.”

Georgia’s runoffs have even created international fascination. Bullock says he’s fielded media inquiries about the contests in recent days from news outlets in Argentina, Chile, Finland, Germany, South Korea and “much of the British media.”