Follow the latest news on the US midterm elections 2022
A pivotal election that will decide which party will control the US Congress entered its final stages on Tuesday evening as polls began to close in eastern states, including the pivotal battleground states of Pennsylvania and Arizona.
Results of some close midterm election races may not be known for days, as election officials tally postal votes.
Voting generally went smoothly, though some sporadic chaos was reported, including in Arizona's Maricopa County, fuelling unsubstantiated claims of fraud from some Republicans.
Candidates who deny the validity of the 2020 election are on the ballot across the country, many for roles that will oversee future elections.
The election is being viewed as a litmus test for Joe Biden's presidency, with Republicans expected to make broad gains in both chambers of Congress.
Most eyes were on the so-called battleground states of Arizona, Georgia, Pennsylvania and Nevada to see which party will win control.
In Arizona's Maricopa County problems were reported early on with vote-tabulating machines at many polling stations, an issue likely to further fuel mistrust in the electoral system.
“It’s obviously disappointing and yes, undoubtedly some people will exploit it for that purpose,” Maricopa County recorder Stephen Richer said.
Issues were reported in as many as 20 per cent of the county's polling locations and teams have been sent to try to fix the problem. Republicans filed an emergency request for voting hours to be extended.
At a polling station in Scottsdale, an affluent suburb of Phoenix, voters expressed dismay.
“Not a lot of confidence in their voting machines. In fact, I'd say zero confidence in their voting machines because there were more ballots being rejected by the machines than being accepted by the machines,” said Robert Moody.
Mr Moody was forced to put his ballot in a locked compartment within the tabulating machine for it to be hand counted later in the day.
In Washington, DC, a Democratic stronghold whose 700,000 residents are denied any representation in the US Congress because the nation's capital is not a state, voters nonetheless turned out to participate in local elections.
Voters said they were motivated by the US Supreme Court’s June decision to scrap the right to abortion and by fears for the electoral process if the Republicans win.
“It’s very important to me as a woman, as a woman of colour and all the things that affect minority women when it comes to women’s minority rights and reproductive health,” said Washington voter Kay McKay.
Democrats spent much of the summer rallying their base over the Supreme Court’s decision to overturn Roe v Wade, but early outrage over the ruling faded in recent weeks, with more and more Americans saying they would vote on the economy and sky-high inflation.
Eyes on polling stations
With voting problems already widespread in Maricopa County, polling stations could become the next hotbed of political activity.
In anticipation, the Justice Department announced it would be expanding its in-person monitoring of polling places across the US to look out for potential voter intimidation tactics and civil-rights violations.
Although election results are expected to trickle in throughout the week, Democrats face slim odds at retaining their power in the House of Representatives and Senate, the two chambers that make up Congress.
Democrats spent much of the summer rallying their base on the Supreme Court's decision to overturn Roe v Wade, but the economy and inflation are voters' most pressing concerns this year.
Republican voters have also ranked immigration as an “extremely important” concern.
If Republicans do win Congress then Kevin McCarthy, tipped to be the next House speaker, would face calls from his party to investigate and possibly impeach Department of Homeland Security Chief Alejandro Mayorkas for the White House's border policies.
Mr Biden said the final two years of his term would be “more difficult” with a Republican-controlled Congress, an understatement given the party's hostility towards his domestic agenda, the chaotic withdrawal from Afghanistan and his son's potential tax crimes.
That could even spillover into future Ukraine funding. Although parties have been united in their support for Kyiv's defence against Russia, Mr McCarthy said there would no longer be a “blank check” for Ukraine if Republicans win the majority.
All of this would probably mean an ineffective final two years of Mr Biden's term before the 2024 presidential election.