Washington — The House is expected to vote in the coming days on whether to impeach Homeland Security Secretary Alejandro Mayorkas for the Biden administration's handling of the situation along the U.S.-Mexico border. 

If successful, it would mark just the second impeachment of a Cabinet secretary in U.S. history, and the first in nearly 150 years.

Here's what to know about Mayorkas and the impeachment effort:

Who is DHS Secretary Alejandro Mayorkas?

Mayorkas was born in Havana, Cuba, in 1959. His family came to the U.S. as political refugees the following year. He attended the University of California at Berkeley and earned a law degree from Loyola Law School.

Mayorkas entered private practice for several years before becoming a federal prosecutor in California. In 1998, he became the youngest U.S. attorney in the country, serving until 2001, when he joined a Los Angeles law firm.

He joined the Department of Homeland Security during the Obama administration. From 2009 to 2013, he worked as the director of U.S. Citizenship and Immigration Services, and was deputy secretary of the department between 2013 and 2016.

He was confirmed to his post as President Biden's top immigration official in February of 2021 after his nomination was briefly stalled over questions about Mr. Biden's border plans. He is the first Latino and first immigrant to lead the department.

Why is Mayorkas being impeached?

Congressional Republicans have aimed to punish the secretary over the administration's handling of the U.S.-Mexico border, accusing Mayorkas of failing to enforce the nation's laws and detain thousands of migrants.

House leaders last year stalled an effort by Rep. Marjorie Taylor Greene of Georgia to force a vote on impeaching Mayorkas, opting to refer the matter to the House Homeland Security Committee. The panel sped through impeachment proceedings this month, holding two hearings. They featured testimony from attorneys general about the impact of migration on their states, as well as mothers who said their children had died in part because of what they see as failures by Mayorkas to manage the southern border. 

This week, the committee released and advanced articles of impeachment against Mayorkas, as House leadership eyes a floor vote on whether to impeach the secretary in the coming days.

Republicans argue that Mayorkas is violating a range of immigration laws, chiefly a statute from the 1990s that requires the federal government to detain certain migrants. Democrats and DHS point out that Congress has never given the executive branch the funding or personnel needed to detain all of the migrants covered by the law.

The articles of impeachment against Mayorkas

The two articles of impeachment against Mayorkas charge him with "willful and systemic refusal to comply with the law" and a "breach of public trust." 

In the first article, the committee Republicans claim that Mayorkas "has repeatedly violated laws enacted by Congress regarding immigration and border security." 

"His refusal to obey the law is not only an offense against the separation of powers in the Constitution of the United States, it also threatens our national security and has had a dire impact on communities across the country," the impeachment resolution said.

The resolution accused Mayorkas and the Biden administration of overstepping their authority and disregarding federal laws by releasing many asylum-seekers into the U.S. and allowing more than 1 million to enter under an authority known as parole. It also referenced a 2023 Supreme Court decision, in which the justices ruled that while states lack standing to compel the executive branch to enforce immigration law, Congress has some tools at its disposal — including impeachment. 

In the second impeachment article, the committee Republicans accused Mayorkas of "knowingly making false statements to Congress and the American people and avoiding lawful oversight in order to obscure the devastating consequences of his willful and systemic refusal to comply with the law and carry out his statutory duties."

The committee pointed to previous testimony from Mayorkas, when he confirmed that the border was "closed" and said the department had "operational control" of the border, as evidence of his false statements to Congress. It also argued that Mayorkas had breached the public trust by "refusing to carry out his statutory duty to control the border and guard against illegal entry." 

The response from DHS and Democrats

In a four-page memo on Jan. 28, the department responded to the impeachment articles, calling them "a distraction from other vital national security priorities and the work Congress should be doing to actually fix our broken immigration laws."

"[Republicans] don't want to fix the problem; they want to campaign on it," the DHS memo said. "That's why they have undermined efforts to achieve bipartisan solutions and ignored the facts, legal scholars and experts, and even the Constitution itself in their quest to baselessly impeach Secretary Mayorkas."

Regarding the first impeachment article, DHS said the department "adheres to the mandatory detention requirements of the [Immigration and Naturalization Act] to the maximum extent possible" and noted that Congress "has never provided the funding for detaining every individual who crosses illegally."

The memo also refuted the claim that Mayorkas lied to Congress, pointing to a distinction between the statutory definition of "operational control" and how the department uses the term internally.

Committee Democrats released a report following the release of the impeachment articles, deriding the effort as a "sham" that fails to provide evidence to support the charges and distracts from the "real challenges" at the border.

"In a process akin to throwing spaghetti at the wall and seeing what sticks, Committee Republicans have cooked up vague, unprecedented grounds to impeach Secretary Mayorkas," the report said. "The MAGA-led impeachment of Secretary Mayorkas is a baseless sham, and the few rational Republicans left in Congress know that — even if they refuse to admit it." 

Constitutional experts who appeared before the committee at the invitation of Democratic members testified during the hearings that Mayorkas' conduct does not constitute an impeachable offense. Frank Bowman, a professor at the University of Missouri's law school, explained that the Constitution reserves impeachment for "Treason, Bribery, or other high Crimes and Misdemeanors."

"There is no serious allegation of which I'm aware that the secretary has done any of those things," Bowman said.

Democrats accused the GOP of pursuing the impeachment for political purposes, as border security has become a central theme of the 2024 Republican campaign. 

"The real reason we are here, as we all know, is because Donald Trump wants to run on immigration as his No. 1 issue in the November election," Rep. Dan Goldman, a New York Democrat, said during the committee hearing on the impeachment articles this week. 

When is the impeachment vote against Mayorkas?

A House vote on the impeachment articles is expected in the coming days, though the exact timeline remains unclear. 

After the committee voted to advance the impeachment articles, House Speaker Mike Johnson said the House will move forward with a vote "swiftly," calling it "long overdue."

Johnson can only afford a handful of Republican defections for the vote to succeed. One GOP lawmaker, Rep. Ken Buck of Colorado, has already said he opposes the effort. Assuming full attendance, Buck's opposition likely means the impeachment push could fail if just two more Republicans vote "no." House leaders might decide against even calling a vote if it becomes clear that it will fall short.

What happens if Mayorkas is impeached?

Mayorkas wouldn't be removed from office immediately if he is impeached. Impeachment is just the first step in removing an official — the matter then goes to the Senate, which has the "sole Power" to hold a trial under the Constitution.

Mayorkas is highly unlikely to be removed by the Senate, which is controlled by Democrats. A two-thirds majority — or 67 senators — would be required to convict and remove him from office.

Exactly how the Senate would proceed once it receives the charges remains to be seen. But the Senate rules for dealing with impeachments and the chamber's own precedents indicate that senators would move quickly to convene a trial.

"Through norms and precedent and tradition, there's not much discretion afforded to the Senate whether or not to hold a trial, because the Senate has always held a trial, unless the impeached party has resigned," says Casey Burgat, the director of the Legislative Affairs Program at George Washington University's Graduate School of Political Management.

But once the trial is underway, a majority of senators can vote to "reinterpret" the rules, Burgat noted, allowing them to maneuver to "quickly dismiss or outright ignore an impeachment trial." Republicans unsuccessfully tried to declare former President Donald Trump's second impeachment unconstitutional on the first day of his Senate trial in 2021.

Senate Majority Leader Chuck Schumer told reporters this week that he would "wait and see what the House does" when asked how the upper chamber would handle a trial. 

Without a conviction, impeachment wouldn't change Mayorkas' ability to carry out his job and remain in the role. But it would be historic, making him the first Cabinet official to be impeached since 1876.

Kaia Hubbard

Kaia Hubbard is a politics reporter for CBS News Digital based in Washington, D.C.