US Republicans announced impeachment proceedings Wednesday against Joe Biden's homeland security chief over the worsening border crisis, as they seek to cement immigration as a major issue in November's presidential election.
Up to 10,000 migrants have been detained daily after crossing illegally from Mexico in what Republicans describe as a humanitarian disaster, while the White House and lawmakers have failed to agree on reforms to stem the influx.
Republicans in Congress, who concluded a probe into Homeland Security Secretary Alejandro Mayorkas in December, accuse the Democrat of creating a national security emergency.
"Our investigation made clear that this crisis finds its foundation in Secretary Mayorkas' decision-making and refusal to enforce the laws passed by Congress, and that his failure to fulfill his oath of office demands accountability," House Homeland Security Committee chairman Mark Green said in a statement.
"The bipartisan House vote in November to refer articles of impeachment to my committee only served to highlight the importance of our taking up the impeachment process."
Mayorkas would be the first Cabinet official impeached since Secretary of War William Belknap in 1876.
A majority of the House would be required to vote that he had committed "high crimes and misdemeanors," prompting a Senate trial that would boot him from office if two-thirds of senators voted to convict.
The border issue unites the fractious Republican Party, but finding the votes for impeachment could still be a challenge, as the House Republican majority has narrowed to just two votes.
Speaker Mike Johnson sought to galvanize the rank-and-file by taking around 60 members to the border town of Eagle Pass, Texas, on Wednesday, where they were to tour a border patrol facility and speak to locals.
Even if an impeachment vote clears the House, a conviction in the Senate is seen as virtually impossible, as 51 of the 100 members in the upper chamber are Democrats.
But the proceedings will still present a headache in an election year for President Biden, who faces his own Republican-led impeachment inquiry over unfounded allegations of corruption, and whose low approval ratings on immigration are among his biggest weaknesses.
Just 38 percent of registered voters in a December Harvard CAPS-Harris Poll said they approved of the Democratic president's handling of immigration, down from 46 percent a month earlier.
Border agents said Tuesday a monthly record of 302,000 migrants were encountered by authorities after crossing illegally in December.
But the Department of Homeland Security (DHS) accused Republicans of "wasting valuable time and taxpayer dollars" on a "political exercise."
"There is no valid basis to impeach Secretary Mayorkas, as senior members of the House majority have attested, and this extreme impeachment push is a harmful distraction from our critical national security priorities," DHS spokeswoman Mia Ehrenberg told AFP in a statement.
The Mayorkas announcement came with the White House and senators from both parties in talks on border security and asylum reforms, with Republicans conditioning aid to war-torn Ukraine on the passage of an immigration bill.
Negotiations have focused on tightening the rules for asylum seekers and expanding expedited removals, with both sides hoping to have a proposal to circulate next week.
Johnson has said he won't accept anything less than the hardline border and immigration bill passed last year by House Republicans, a non-starter in the Senate.
Texas governor Greg Abbott, a staunch Republican, has sought to take the immigration debate nationwide by sending thousands of migrants to Democratic-led northern cities.
Mayors in New York, Denver and Chicago have pressured Biden to take urgent action.
