Americans voted on Tuesday in pivotal midterm elections with Democrats hoping to seize control of Congress and impose the first significant checks on Donald Trump's chaotic second term in the White House.
Republicans losing the House would give Democrats the power to stall Trump's legislative agenda and launch sweeping investigations of his administration. A Senate defeat would also threaten his ability to appoint Supreme Court justices and senior officials.
The election amounts to a nationwide judgment on Trump, with the mood turning sharply against Republicans amid anger over soaring living costs and the war against Iran.
All 435 House seats and 35 of the 100 Senate seats are at stake, along with governorships in 36 states. Democrats need only three House gains and a net four seats in the Senate to wrest both chambers from Republican hands.
Trump returned to office last year promising to bring down prices, but inflation, tariffs and fuel costs inflated by the Middle East conflict have squeezed Americans.
The 80-year-old's approval rating has hovered near the low 30s.
In the suburbs of Atlanta, Georgia, retired teacher Jane Callum, 77, was among Democrats canvassing for Senator Jon Ossoff who framed the race as a watershed moment for the country's future.
"I really feel an obligation to do everything that I possibly can to change the direction that our country is going in now, and put it more on the path to democracy and away from autocracy," she told AFP.
- Economic discontent -
Republicans insist that Trump's tax cuts and immigration crackdown will benefit Americans, and they are portraying Democratic candidates as left-wing radicals.
But in his final public campaign appearance on Monday, Trump barely touched on the economy and spent most of the time in a rambling talk about his problem-plagued renovation of Washington's Reflecting Pool.
"This is the last day before the midterm elections, the most important midterm I believe in our lifetime," he said, 26 minutes into the speech, before quickly returning to talking about renovations.
Senate Democratic leader Chuck Schumer branded it a "pathetic closing message."
Some Republican supporters remain confident.
"We're going to win. As a matter of fact, we've probably already won," Texas military veteran Yvonne Clouser told AFP.
But while Republicans hold a 53-47 Senate majority, the political battlefield is extending into conservative states like Kansas, Texas, Iowa, Ohio and Alaska.
Democrats must also defend competitive seats, including in Michigan, where a bitter internal dispute saw congresswoman Haley Stevens endorse Republican Mike Rogers rather than the Democratic nominee, Abdul El-Sayed.
Decision Desk HQ's final forecast projected 241 House seats for Democrats against 194 for Republicans, and a narrower 52-48 Democratic Senate majority.
- Disputed results? -
Polls can underestimate one party's support, and Republicans hope their voters turn out in force on Election Day.
More than 57 million Americans had already voted early before Tuesday, indicating the high energy.
The campaign has attracted more than $11 billion in political advertising, while mega-rich Trump ally Elon Musk has poured hundreds of millions of dollars into Republican political efforts.
As soon as polls close, concerns will mount over whether results will be accepted by the Republicans.
Trump, who tried to overturn his 2020 election defeat, has repeatedly alleged widespread voter fraud and accused Democrats -- with no evidence -- of cheating.
The Justice Department, run by a close Trump ally, has already sued to potentially block certification of Alaska's Senate race if Republican incumbent Dan Sullivan narrowly loses, although a court ruled against the effort on the eve of the election.
And the Supreme Court rejected on Monday an emergency bid to force California to set aside the mail-in ballots of more than 20,000 people on the grounds they may not be American citizens.
Trump, who will watch the midterms results at the White House on Tuesday night, signaled that if he does lose control of Congress he could simply defy Democrats.
"I veto everything," he told a podcast on Monday, although he said he might strike deals with Democrats eventually.
