Midterm election vote counting was still ongoing in pivotal US states on Thursday as control of the Senate hinged on Arizona, Nevada and Georgia.

Arizona's Democratic incumbent Senator Mark Kelly appeared to be in the lead as of Thursday morning. 

Kelly, a former astronaut, is facing challenge from the Trump-backed ultra-conservative Blake Masters. 

But it was still too early to call the races for Senate seats in Arizona and Nevada, where counting votes could take several more days. Georgia, meanwhile, will head to a runoff election in December.

Democrats and Republicans' unexpected performance

Although Republicans seem set to have power in the 435-seat House of Representatives, they are likely to do so with lower numbers than the predicted "red wave."

"It didn't happen," US President Joe Biden, a Democrat, said on Wednesday in his first speech since the polls closed. 

Democrats have outperformed predictions, despite Biden's low approval rates and rising inflation.

If final results show further losses to Republicans, the midterm could mark the best performance by a sitting president's party in years.

"It was a good day I think for democracy, and I think it was a good day for America," Biden said.

Several Democratic nominees made historic firsts as women, Black and LGBT candidates were elected to positions of power, including governors and representatives. 

What happens next?

A runoff election in the state of Georgia is scheduled for December 6. Its outcome could determine whether Democrats or Republicans will control the Senate.

Republican Herschel Walker, a former American football star backed by Donald Trump, is running against Democratic incumbent Raphael Warnock, a 53-year-old Black pastor.

A Democratic-run Congress would help Biden pass the legislation he supports. 

While the 2022 election has yet to be end, all eyes are already on the 2024 presidential election.

Former US President Donald Trump was expected to announce running for presidency shortly after the midterm election. 

But several Trump-backed candidates have lost, and his likely challenger for the party's nomination, Florida's Ron DeSantis, added to his growing popularity by holding on to his governor's seat. 

Meanwhile, Biden said he would announce his decision about reelection "early next year."

fb/wmr (AP, AFP, Reuters)