Republican J.D. Vance won Ohio's U.S. Senate race in Tuesday's midterm elections, but control of the chamber remained up for grabs with several contests too close to call.
Meanwhile, with polls closed across the country, Republicans were still favored to wrest control of the U.S. House of Representatives from President Joe Biden's Democrats based on early returns, though the prospects of a "red wave" in which they picked up dozens of seats appeared to have dimmed.
Republicans had flipped four Democratic seats in the U.S. House, Edison Research projected, one fewer than they would need to capture a majority and cripple Biden's legislative agenda.
But that number could change as 100 of the 435 House races had yet to be called, including some with vulnerable Republican incumbents.
Vance, author of the hardscrabble memoir "Hillbilly Elegy," had been favored over Democratic Representative Tim Ryan, who emphasized his blue-collar background and criticized the left wing of his own party.
Pivotal Senate races in Pennsylvania, Nevada, Georgia and Arizona all looked like toss-ups. The Georgia race could end up in a Dec. 6 runoff, possibly with the Senate at stake. Democrats currently control the 50-50 Senate with Vice President Kamala Harris able to break any ties.
Early results suggested Democrats would avoid the type of wipeout election that some in the party had feared, given Biden's sagging approval rating and voter frustration over inflation.
"Definitely not a Republican wave, that's for darn sure," Republican U.S. Senator Lindsey Graham told NBC in an interview. He held out hope that the party would take a majority in the Senate: "I think we're going to be at 51, 52, when it's all said and done."
Even a narrow Republican majority in the House would be able to block Biden's priorities while launching politically damaging investigations into his administration and family.
In addition to every House seat, 35 Senate seats and three dozen governors' races are on the ballot. Florida Governor Ron DeSantis, a leading contender for the Republican presidential nomination in 2024, defeated Democratic Representative Charlie Crist, Edison projected.
The final outcome of the congressional races is unlikely to be known any time soon. More than 46 million Americans voted ahead of Election Day, either by mail or in person, according to data from the U.S. Election Project, and state election officials caution that counting those ballots will take time.
High inflation and abortion rights were voters' top concerns, with about three in ten voters picking one or the other as their top concern, exit polls showed. Crime, a major focus in Republican messaging in the campaign's final weeks, was the top issue for just about one in ten voters.
One sign of Republican strength could be found in several competitive House districts that Biden would have won in 2020 under recently redrawn boundaries.
In Virginia's 2nd congressional district, for instance, Democratic U.S. Representative Elaine Luria lost to Republican challenger Jennifer Kiggans in a district Biden carried by two points.
Local officials reported isolated problems across the country, including a paper shortage in a Pennsylvania county. In Maricopa County, Arizona - a key battleground - a judge rejected a Republican request to extend voting hours after some tabulation machines malfunctioned.
The problems stoked evidence-free claims among Trump and his supporters that the failures were deliberate.
Scores of Republican candidates have echoed Trump's false claims that his 2020 loss to Biden was due to widespread fraud. In Pennsylvania, Republican gubernatorial candidate Doug Mastriano, who sought to overturn the state's election results after Trump lost, was defeated by Democrat Josh Shapiro.
In New Hampshire, Democratic Senator Maggie Hassan prevailed over Republican Don Bolduc, a retired general who also backed Trump's baseless assertions, in a race that Republicans had once viewed as a top opportunity.
In swing states such as Arizona, Michigan and Nevada, the Republican nominees to head up the states' election apparatus have embraced Trump's falsehoods, raising fears among Democrats that, if they prevail, they could interfere with the 2024 presidential race.
"They deny that the last election was legitimate," Biden said on a radio show aimed at Black voters. "They're not sure they're going to accept the results unless they win."
Trump, who cast his ballot in Florida, has frequently hinted at a third presidential run. He said on Monday that he would make a "big announcement" on Nov. 15.
A Biden adviser, anticipating a tough evening, said Democrats had done the best they could given higher gas prices and inflation, in part due to Russia's invasion of Ukraine.
The party that occupies the White House almost always loses seats in midterm elections, but Democrats had hoped the Supreme Court's June decision to overturn the nationwide right to abortion would help them defy that history.
But stubbornly high annual inflation, which at 8.2% stands at the highest rate in 40 years, has weighed on their chances throughout the campaign.
"The economy is terrible. I blame the current administration for that," said Bethany Hadelman, who said she voted for Republican candidates in Alpharetta, Georgia.
A Reuters/Ipsos poll this week found just 39% of Americans approved of the way Biden has done his job. Some Democratic candidates deliberately distanced themselves from the White House as Biden's popularity languished.
Trump's polling is similarly low, with just 41% of respondents to a separate recent Reuters/Ipsos poll saying they viewed him favorably.
In Congress, a Republican-controlled House would be able to thwart Democratic priorities such as abortion rights and climate change, while a Republican Senate would hold sway over Biden's judicial nominations, including any Supreme Court vacancy.
Republicans could also initiate a showdown over the country's debt ceiling, which could shake financial markets.
Republicans will have the power to block aid to Ukraine if they win back control of Congress, but analysts say they are more likely to slow or pare back the flow of defense and economic assistance