American voters have rushed the polls with days to go before Tuesday’s midterm elections that will decide the Congress President Donald Trump will have to deal with in his final two years.

Fifty million voters had already voted with five days to go  — 10 million more than at the same point in 2022, according to an Associated Press analysis of voting data.

The increases have been particularly pronounced in states with competitive Senate races — including Iowa and Kansas, where early voting is up roughly 30 per cent.

The University of Florida Election Lab found four to five million early votes had been cast each day, a much higher rate than in most previous elections, the BBC reports.

Overall turnout appeared on track to outpace 2020 and possibly 2018, which beat the 1914 record for overall turnout in a midterm election.

Democrats and Republicans each hope the rise in early voting favours them as they fight for control of Congress in an election that has turned largely on affordability issues and the president’s unpopularity.

Trump rallied with Republican supporters in Florida and former president Bill Clinton appealed to Democrats just two states over in Mississippi, both beseeching their bases to get out and vote.

“These are the most important midterm elections ever,” Trump told his crowd in Daytona.

The US midterm election are shaping up as a close contest, especially in battleground states. Photo: AAP

Trump has also signalled that his administration plans to aggressively pursue an investigation into an alleged scheme to confuse voters in Alaska, another state with a competitive Senate race.

US Attorney Michael Heyman in Alaska confirmed on Friday a probe — underway for months — into a candidate with the same name as the Republican incumbent.

Heyman said law enforcement assets were surged to the state this week after The New York Times reported that Democratic Senate candidate Mary Peltola’s campaign appeared to be involved in recruiting Dan J. Sullivan to run in the race alongside her Republican opponent, Senator  Dan Sullivan.

Peltola denied on Thursday that she knew anything about the work to add another candidate with her opponent’s name to the ballot.

The Justice Department said it wants to isolate ballots ranking Dan J. Sullivan to test the level of “confusion” among voters.

Trump has also rescheduled rallies in Kansas and Iowa on Sunday after previously saying he didn’t feel the need to go.

“I thought this was going to be my last one, Byron,” Trump said to Republican gubernatorial candidate Byron Donalds at his Daytona rally.

“I thought this was it. I thought I could relax. Twenty-eight days in a row of this crap is a lot,” he said.

In Michigan, where Democrats had hoped to put a bruising Senate primary behind them after progressive Abdul El-Sayed narrowly defeated representative Haley Stevens in August, fighting between the rivals again dominated headlines.

Stevens re-emerged in the final week before the general election, appearing on CNN to reaffirm that she would vote for El-Sayed while calling on him to repair relations with Jewish and Black voters.

Then on Friday she released a lengthy statement on social media criticising her former rival and demanding he condemn an advertisement linking US support for Israel to rising grocery prices.

“Abdul promises to get money out of politics,” Stevens wrote. “He can begin by getting Israel out of his explanation for everything Michigan cannot afford.”

In Texas, where voters are deciding closely watched Senate, House and governor’s races, more than 6.3 million Texans had voted early as of Wednesday, compared with 4.2 million at the same point four years ago.

Advance voting has also increased more than 30 per cent from the same point four years ago in Maine, Michigan, North Carolina and Kansas, states with competitive Senate races.

In South Carolina, where voters are choosing a successor to the late Republican Senator Lindsey Graham, early voting was up 83 per cent.

Historic amounts of money have flowed into this year’s midterm elections.

Republicans have expressed concerns about their voters not turning out in the midst of voter dissatisfaction with Trump and high costs, issues Democrats have focused on in their campaigns.

-with AAP, AP, Reuters