House Republicans have forwarded two articles of impeachment against Alejandro Mayorkas, President Joe Biden's leading border security official, to the Senate.
The Republican-controlled U.S. House of Representatives is looking to initiate a trial, but the Democratic-majority Senate is expected to dismiss the charges without a trial or hold a brief trial that concludes without a conviction.
House Republican managers, tasked with presenting their case for the removal of the Homeland Security Secretary, formally presented their charges to the Senate. They accused Mayorkas of failing to uphold U.S. immigration laws and providing false information to Congress.
Senate Majority Leader Chuck Schumer is expected to try to stop the trial before it starts. But if it goes ahead, the 100 senators will be sworn in as jurors Wednesday for a trial that could last at least a week.
Mayorkas, who took office at the beginning of the Biden administration, becomes the first Cabinet secretary to face impeachment in almost 150 years.
In February, House Republicans voted to impeach Mayorkas over his management of the southern border by a slim margin, following an unsuccessful attempt earlier.
After taking control of the House last year, Republicans immediately targeted Mayorkas, blaming him for the surge in border crossings. This came amid mounting pressure from their base to hold the Biden administration accountable on a critical campaign issue.
However, several constitutional experts have said the evidence presented by Republicans does not meet the stringent criteria outlined by the U.S. Constitution for high crimes and misdemeanors.
Democrats also claim that House Republicans are driven by political motives and have not provided evidence of illegal actions.
Mayorkas has dismissed criticism of his leadership, and the Department of Homeland Security (DHS) has alleged the impeachment effort against him as a groundless political assault.
Earlier on Tuesday, Mayorkas testified before the House Homeland Security Committee for nearly three hours. Although he was called to testify about his agency's budget for next year, the topic of impeachment dominated the hearing.
Former President Donald Trump, who is running against Biden in the upcoming election, has consistently put immigration as a central theme of his campaign.