Voting stations have begun closing in the US midterm elections, with exit polls suggesting the main issues for voters were inflation and abortion.
Some 32% of voters cited rising prices as most important, while 27% rated abortion as their priority, according to the Edison research exit poll.
The emphasis on abortion could buoy Democrats who have used the issue to motivate their base to vote in numbers.
The entire House of Representatives and a third of the Senate are up for grabs.
Republicans are widely expected to pick up the five seats they need to control the House.
Control of the Senate, however, could come down to a handful of neck-and-neck races and those results might not be known for days.
The midterms will shape the fate of President Joe Biden’s agenda.
The vote is also widely anticipated to serve as a launchpad for a 2024 White House comeback bid by former President Donald Trump.
Despite delivering on promises to lower prescription drug prices, expand clean energy and revamp US infrastructure, Mr Biden has seen his popularity suffer following the worst inflation in four decades.
But Republicans have their own political vulnerability on the issue of abortion following the conservative-dominated Supreme Court’s decision this year to roll back a US constitutional right to the procedure.
The ruling triggered a swathe of restrictions on abortion in Republican-led states, energising liberal voters around the country and raising hopes among Democrats they might defy the historical political gravity that typically weighs on a governing party in the midterms.
According to exit polls by the BBC’s US partner CBS News, abortion was the top issue for Democratic voters, while Republicans and independents rated inflation as their top issue.
No major glitches were reported with voting on Tuesday beyond a few isolated problems typical of any election day.
Mr Trump nevertheless seized on the hiccups in a bid to cast doubt on the integrity of the vote.
He has used the midterms to set the stage for an apparent comeback, teasing an announcement next week.
Mr Biden – who is not on the ballot on Tuesday – has argued that a Republican victory could weaken democracy.
Key state officials who have echoed Mr Trump’s false claims of a stolen presidential election in 2020 are on the ballot on Tuesday, and they could supervise how future elections are run.
Early voting allowed some 44.5 million Americans across the country to cast their ballots before election day.
US officials said with voting under way that they did not see a “specific or credible threat” to disrupt election infrastructure.