Arizona and Nevada election workers were toiling on Friday to tally hundreds of thousands of ballots that could determine control of the U.S. Senate and the shape of President Joe Biden’s next two years in office, in a vote count that officials in the two battleground states warn could drag on for days.

Winning both contests would give either Democrats or Republicans a Senate majority, while a split would transform a December 6 runoff Senate election in Georgia into a proxy battle for the chamber.

Political analysts are anticipating a rush of campaign funds into Georgia as Republicans and Democrats gear up for the final battle of the 2022 midterm elections.

In Arizona, law enforcement officials remained on high alert for potential protests, with barricades and security fencing erected around the Maricopa County elections department, where dozens of officials are working 18-hour days to verify outstanding ballots and tabulate votes.

Kari Lake, the Republican gubernatorial candidate in Arizona, has criticized election officials in Maricopa County, the state’s most populous, as “incompetent” and “despicable,” accusing them of deliberately delaying the vote counting.

Bill Gates, chairperson of the Maricopa County Board of Supervisors and a Republican, bristled at Lake’s comments.

“Everybody needs to calm down a little bit and turn down the rhetoric,” he told reporters. “That’s the problem with what’s going on with our country right now.”

Control of House, Senate still in question

In the fight for control of the House of Representatives, Republicans were inching closer to becoming the majority and ending four years of rule by Biden’s Democrats. That would give Republicans veto power over Biden’s legislative agenda and allow them to launch potentially damaging investigations into his administration.

Republicans had secured at least 211 of the 218 House seats they need for a majority, Edison Research projected late on Thursday, while Democrats had won 199. Many of the races where winners have not yet been determined are in Arizona, California and Washington state.

Despite the real possibility that they may lose the House, Democrats have still cheered their success in curbing their predicted losses after they galvanized voters angry over the Supreme Court’s decision in June to overturn the constitutional right to an abortion.

The Republican House leader, Representative Kevin McCarthy, has already announced his intention to run for speaker if Republicans take over, an outcome he has described as inevitable.

It is unclear whether a challenger to McCarthy will emerge, but some of the most conservative House Republicans have expressed doubts that he has enough votes yet to become speaker, the most powerful official in the House.

Meanwhile, Republican infighting in the Senate broke into the open on Friday as senators urged the postponement of a Wednesday leadership election so that they have time to discuss why the party did not fare better on Tuesday.

Senator Mitch McConnell is hoping to continue as Republican leader, despite sniping from former President Donald Trump and other conservatives.

Counting could take until next week

Officials overseeing vote counting in the Arizona and Nevada Senate races, where Democratic incumbents are trying to fend off Republican challengers, have said it could take until next week to tally some 520,000 uncounted mail-in ballots. Most of those were in Maricopa County, which encompasses Phoenix.

Their work is slowed by the need to match signatures on mail-in ballots to voter registration signatures after high numbers of such votes were dropped off on Election Day.

By midday on Friday, Democratic Senator Mark Kelly had extended his lead over Republican Blake Masters to 115,000 votes, with about 80% of the vote tallied, while Arizona Democratic gubernatorial candidate Katie Hobbs had extended her narrow lead over Trump-backed Republican Kari Lake to 27,000.

Some of Trump’s most high-profile endorsed candidates lost pivotal races on Tuesday, marring his status as Republican kingmaker and leading several Republicans to blame his divisive brand for the party’s disappointing performance.

While Trump has not officially launched a third White House campaign, the former president has strongly suggested he will do so and is planning a “special announcement” at his Florida club on Tuesday.