What's at stake as Republicans seek to open impeachment inquiry into Biden?

Republican lawmakers have launched an investigation into the possible impeachment of President Joe Biden, but such a prospect remains highly unlikely.

Republican House members accuse Biden, a Democrat, of having "lied" to the American people about his son Hunter's controversial business dealings abroad.

Here are points to understand what may lie ahead.

What is the procedure?

The Constitution provides that Congress may impeach a president in the event of "treason, bribery or other high Crimes and Misdemeanors."

Impeachment by the House — the political equivalent of a criminal indictment — would spark a "trial" by the Senate.

It is a two-stage process. First, the lower House of Representatives conducts a vote by a simple majority on articles of impeachment detailing the charges against the president.

In the event of approval, the Senate puts the president on trial. At the end of the debate, the 100 senators vote on each article. A two-thirds majority is required to convict, in which case impeachment is automatic and final. Otherwise, the president is acquitted.

No president has ever been removed from office by impeachment. While Donald Trump was in office, the House approved articles of impeachment in 2019 and again in 2021. Both times, the Senate acquitted.

The US Senate is controlled today by Democrats, making Biden's impeachment improbable.

Why now?

The Trumpist wing of the Republican Party has pushed for Biden's impeachment since his 2020 election.

After securing a majority in the House this year, Republican lawmakers say they have "serious and credible allegations" against Biden, Speaker Kevin McCarthy now says.

McCarthy won his job back in January by making a series of deals with the hard-right lawmakers.

"McCarthy is doing this for a very simple reason: If he doesn't, he'll be replaced as speaker," political scientist Larry Sabato told AFP.

The Democrats, for their part, say any impeachment inquiry allows Trump to turn the House of Representatives into an arm of his 2024 presidential election.

An impeachment inquiry, in the meantime, would distract attention from the massive legal troubles weighing on Trump, who faces 91 criminal charges that will play out in four trials over the coming year.

What are the consequences?

"My guess is that this will backfire on the Republicans," predicts Sabato, who says "there is thin, if any, evidence" for their claims about Biden.

Yet Biden's image of rectitude could be tarnished by the televised hearings on his son's affairs.

On another front, lawmakers have knives out for a pending battle over Republican demands for major budget cuts.

If lawmakers cannot agree on spending bills to fund the US government by a September 30 deadline, the government will slowly shut down.