A massive 40 million Americans have already voted early, according to reports and both sides were predicting victory.
Bullish Republicans have promised to deliver a "wake-up call" to Joe Biden and retake Congress in this week's crucial midterm elections, as the US president's Democrats insisted they were still in the fight with two days to go.
Biden and his predecessor Donald Trump have been pulling out the stops to draw voters to the polls in Tuesday's contest — which Biden says marks a defining moment for US democracy.
After rival Saturday night rallies in battleground Pennsylvania, both men had new appearances set for Sunday — Biden in New York, Trump in Miami — while senior party leaders took to the airwaves seeking out every last American vote.
A massive 40 million Americans have already voted early, according to NBC News on Sunday, and both sides were predicting victory.
But the latest polls have put Democrats on the defensive, while Senator Rick Scott, chair of the National Republican Senatorial Committee, summed up the mood in his party by predicting "a great night" in both chambers of Congress.
Fellow Republican Glenn Youngkin, the governor of Virginia, told ABC News talk show "This Week" that his camp was the one now "offering common-sense solutions" to pressing issues like sky-high inflation and crime.
"This is going to be a wake-up call to President Biden," Youngkin said.
With Republican figurehead Trump doubling down on voting conspiracy theories ahead of the midterms, and several candidates in his camp casting doubt on the upcoming results, party leaders sought to assure voters that Republicans will accept the outcome — even if they lose.
'A defining moment'
US midterm elections are typically seen as a referendum on the president in power, whose party tends to lose seats in Congress, particularly if — as with Biden — the president's approval rating is under 50 percent.
Polls put Republicans ahead in the fight for the House, and also show them gaining momentum in key Senate races as voters seek to take out frustration over four-decade-high inflation and rising illegal immigration.
A new NBC News poll contained a particularly worrying result for Democrats: It found that a whopping 72 percent of voters believed the country is headed in the wrong direction, to 21 percent who saw it as being on the right track, auguring badly for the party in power.
But there was one glimmer of good news for the president's party: After trailing earlier, Democrats have caught up with Republicans in election interest, with an identical 73 percent of each party's voters expressing high interest.
Speaking to thousands in a Philadelphia arena, Biden cited Trumpists' growing support for conspiracy theories to highlight what is at stake.
"Democracy is literally on the ballot. This is a defining moment for the nation," Biden warned.
Trump prepares for 2024
Trump himself was attending a rival rally to boost Fetterman's opponent, TV celebrity doctor Mehmet Oz, and Shapiro's far-right opponent Doug Mastriano.
In a rambling speech, Trump defended his attempts to overturn the 2020 election and urged Americans to "vote Republican in a giant red wave" — while teasing his potential new White House run in 2024.
"I promise you in the very next very, very, very short period of time, you're going to be so happy," Trump told his supporters.
Democrats have pushed back against the narrative of an inevitable Republican takeover of Congress.
"We're going to hold this majority," congressman Sean Patrick Maloney, who heads the Democratic congressional campaign arm, insisted to NBC, saying Biden unfairly received a "bum rap" for inflation while getting too little credit for successes like job growth.
But polls suggest Biden's Democrats have struggled to convince voters on kitchen-table issues central to the election — and there is little indication that Biden's dire warnings of a threat to democracy have turned the tables in their favor.