Donald Trump wants to see President Joe Biden impeached, and the former president’s allies in Congress and his 2024 GOP presidential rivals are eager to join that fight as his own legal challenges mount.

Trump’s chief opponent, Ron DeSantis, this week said the House Republicans “are absolutely within their rights” to consider an impeachment inquiry against Biden. Former UN ambassador Nikki Haley, also running for president, said Republicans would be “justified to do it.” And House GOP leaders aligned with Trump are foreshadowing what’s ahead.

“House Republicans will leave no stone unturned,” said Elise Stefanik of New York, the fourth-ranking House GOP leader and a top Trump ally, who is sometimes mentioned as a potential vice presidential pick.

This week, the prospect of impeaching Biden over the business dealings of his son, Hunter Biden, emerged from the far corners of the GOP’s right flank to the mainstream in the Republican Party.

President Joe Biden attends his granddaughter Maisy Biden's commencement ceremony with Jill Biden and children Hunter Biden and Ashley Biden at the University of Pennsylvania. Photo / AP

Speaker Kevin McCarthy announced on Fox News that the House may open an impeachment inquiry into Biden, and expanded on his plans at a Tuesday press event at the Capitol.

Behind closed doors Wednesday, however, the Republican speaker told GOP colleagues it’s early in the impeachment process, and McCarthy acknowledged there’s still much that is unknown about Joe Biden and whether he had any awareness or involvement in his son’s business deals that would arise to an impeachable offence.

“The speaker went through what we know and what we don’t know,” said Tom Cole, a seasoned lawmaker and committee chairman.

“There’s a lot we don’t know — we don’t know if any money went directly to President Biden or not,” Cole said, explaining the message to the House GOP. “That’s what they do the investigations about.”

Rep Marjorie Taylor Greene said McCarthy also told them if it comes to a Biden impeachment inquiry, he’s going to ask that “you be with me on this”.

Greene, a Trump ally backing impeachment, said no one rose during the private meeting to object.

By putting Biden on notice that the House is considering an inquiry, the Republicans are elevating a once rare congressional check on executive power — the formal impeachment charges over high crimes and misdemeanours — into yet another tool being wielded in party politics.

It’s a political escalation, urged on by Trump, after his own two impeachments. The prospect of a Biden impeachment inquiry also comes as Trump faces mounting legal cases, including a potential federal indictment in the investigation led by Special Counsel Jack Smith over his efforts to overturn the election in the run-up to the January 6, 2021 attack on the Capitol.

Proud Boys members Zachary Rehl (left) and Ethan Nordean (right) walk toward the US Capitol in Washington. Photo / AP

Trump is the only president in US history that has been twice impeached — first in 2019 over his phone call urging Ukrainian President Volodymyr Zelensky to dig up dirt on the Bidens or risk losing US military aid, and again in 2021 in the aftermath of the January 6, 2021 attack on the Capitol by Trump supporters trying to overturn Biden’s election.

Now, as the Republican party’s frontrunner for the nomination to take on Biden in 2024, Trump has long seethed over his impeachments at the hands of House Democrats. McCarthy has suggested the Trump impeachments could be expunged, as proposed by Stefanik and Greene. But Trump wants Biden to face similar impeachment charges.

“They impeach me over a ‘perfect’ phone call, and they don’t impeach Biden,” Trump posted online in capital letters this week, calling the current president “corrupt”.

Last week, at a Fox News town hall in Iowa, Trump expressed similar complaints asking: “Why aren’t they impeaching Biden? ... Why isn’t he under impeachment?”

House Republicans in various committees are probing the Bidens and suggesting the president may have been aware or involved in his son Hunter Biden’s work, particularly when the younger Biden served on the board of the Ukrainian energy firm Burisma.

The Republicans in Congress point to testimony from two IRS whistleblowers who testified last week the Justice Department slow-walked their investigation into Bidens, a claim the agency rejects. The Republicans also publicly released what the FBI says is unverified information from a confidential informant alleging Burisma payments to the Bidens as bribes, though other documents show a top company official disputing any payments were made.

Hunter Biden had agreed to plead guilty to misdemeanour charges of tax evasion stemming from a federal investigation, but the deal unravelled Wednesday when a judge raised questions about it.

“I’ve seen enough. We need a special counsel who has jurisdiction over any and all Biden family investigations,” Chris Christie, another Trump rival in the 2024 race, said on social media.

The White House has declined to engage in specific questions about any House GOP impeachment inquiry against Biden.

“They can do whatever it is that they wish to do, but we’re going to stay focused,” White House press secretary Karine Jean-Pierre said earlier this week, pointing to the “real priorities that the American families care about”.

Biden himself has repeatedly said that he does not talk with his son about his overseas business dealings.

As Hunter Biden appeared in court Wednesday, the press secretary issued a statement: “As we have said, the president, the first lady, they love their son, and they support him as he continues to rebuild his life.”

Not all Republicans are on board with the House’s plans to consider an impeachment inquiry, but those who object may face political retribution from Trump.

Senate Republican Leader Mitch McConnell said he understands House Republicans may be incentivised to launch an impeachment inquiry after Trump was impeached twice when Democrats had control of the chamber.

But the Kentucky Republican warned fellow Republicans of continuing down this path.

“Impeachment ought to be rare rather than common,” said McConnell, who has long endured Trump’s ire and hasn’t spoken to him since the month before the Capitol attack. “I think this is not good for the country when we have repeated impeachment.”

Trump this week singled out other Republican senators, including John Cornyn of Texas and Mitt Romney of Utah, who had expressed their reluctance to launch impeachment proceedings.

House Democrats have declared the effort to impeach Biden’s political extremism and signalled they will oppose it.

“I’m very well aware of how important it is to follow the facts and the evidence before you reach any conclusions — and the Republicans are doing the reverse,” said Dan Goldman of New York, a chief prosecutor in the House’s first impeachment of Trump in 2019.

“What they are talking about now is pure political retribution that is not based on facts and evidence,” he said, adding that’s “abusing the impeachment power of the Congress”.