Confident of emerging victorious from the simmering cauldron of the US midterm elections, Republicans are cooking up a buffet of legislative priorities for the new Congress -- and topping the menu is a dish best served cold.

The party of former president Donald Trump has had to watch powerlessly from the opposition benches as its recalcitrant leader has spent years fending off criminal and congressional probes.

But the Republicans are expected to regain the House of Representatives in November, and are plotting revenge on Trump's foes in Congress, the White House and law enforcement with investigations of their own.

One major target could be President Joe Biden himself, according to Republican congresswoman Nancy Mace, who has confirmed longstanding speculation that some colleagues are mulling impeachment next year.

"I believe there is pressure on the Republicans to put that forward and have that vote," she told NBC in September. "I think that's what some folks are considering."

The House Oversight Committee's top stated priority, though, will be intensifying scrutiny of the Democratic leader's son, Hunter Biden, who is already being investigated by the FBI over his business.

The battle for the 100-seat Senate, currently divided evenly between the two parties, has been described as a "jump ball" by Republican leader Mitch McConnell.

But a gain of just six seats would hand the "Grand Old Party" control of the House, paving the way for two years of intense scrutiny of the Biden administration.

'500 requests'

Party leaders have so far declined to endorse the impeachment move publicly.

But they have vowed to "conduct rigorous oversight to rein in government abuse of power and corruption" among a package of broad policy priorities unveiled in the final weeks of the election campaign.

"House Republicans have put the Biden administration on notice -- with more than 500 requests for information and documents," their prospectus says.

"When backed by subpoena power, the American people will finally get some of the answers they deserve."

Several House Republicans and Trump administration figures have defied subpoenas to appear before Democratic-led probes, including the investigation into the 2021 insurrection.

But Republicans have pledged nevertheless to compel testimony on multiple aspects of decision-making by the Democrats.

Subjects for the planned investigations include the White House's handling of the fraught withdrawal from Afghanistan, illegal immigration at the Mexico border and the origins of the Covid-19 virus.

Homeland Security Secretary Alejandro Mayorkas, who is in charge of immigration, is a prime target for impeachment.

Republicans have also vowed to investigate Anthony Fauci after locking horns repeatedly with Biden's soon-departing chief medical advisor over Covid-19 vaccines, mask mandates and other pandemic-related issues.

"Dr. Fauci was warned by top scientists early on that the virus looked genetically manipulated and likely leaked from the Wuhan lab," top Republican James Comer, who expects to lead the oversight committee next year, said in a statement.

"Despite these facts, Dr. Fauci dismissed these ideas in public as conspiracy theories."

Comer is contradicted by John Hopkins University, which said in August that recent research confirming a Chinese seafood market as the origin of the pandemic was the "death knell for any alternative theories."

'Hypocrisy'

Another target of Republican scrutiny could be the FBI's handling of the raid at Trump's Florida beach club to recover illegally stored classified documents.

"Attorney General (Merrick) Garland: preserve your documents and clear your calendar," House Republican leader Kevin McCarthy tweeted the day of the search, accusing Democrats of the "weaponized politicization" of the Justice Department.

US media has reported that the Republicans are also plotting revenge on the panel investigating the 2021 US Capitol assault, which has uncovered a slew of damning evidence about Trump's role in the riot.

Republicans will also look into special counsel Robert Mueller's investigation into the Russian attack on the 2016 US election, which revealed extensive contacts between the Trump campaign and Russian government and intelligence operatives.

News of the investigations has prompted a withering response from Democrats, who have dismissed the Hunter Biden probe in particular as a Republican "obsession."

"Unlike former president Trump and his family, who used their senior White House positions to advance their own financial interests -- and whom Republicans have blindly defended -- Hunter Biden is a private citizen who is not a member of the administration," one aide told The Washington Post.

"Republicans' hypocrisy is not lost on the American people."

© Agence France-Presse