Homeland Security Secretary Alejandro Mayorkas will face House Republicans who have been making the case to potentially impeach him over his handling of the US-Mexico border in a House panel hearing Wednesday.

Over recent months, House Republicans have started to lay the groundwork for potential impeachment proceedings against Mayorkas, who, they argue, has failed to enforce the US southern border.

And on Wednesday, Mayorkas will appear before the House Judiciary Committee, the panel where impeachment would originate, for a hearing on oversight of the Department of Homeland Security. The hearing comes as House Homeland Security Chairman Mark Green, a Republican from Tennessee, has launched a five-phased investigation into Mayorkas.

The handling of the US-Mexico border has been an ongoing point of contention between Republicans and President Joe Biden, whose administration has grappled with unprecedented migration in the Western hemisphere. While border crossings remain high, numbers dipped in June to the lowest monthly border encounters since February 2021.

Administration officials have credited a series of measures taken on the US-Mexico border, as well as new policies, for the dramatic drop in border crossings. But the administration's actions have done little to quell concerns among Republicans who continue to seize on the issue.

In a warning shot Tuesday, House Judiciary Chairman Jim Jordan, an Ohio Republican, requested that Mayorkas be ready to provide data on border arrests and deportations, among a host of issues, in a letter to the DHS secretary.

While the impeachment of Mayorkas was once thought of as inevitable, some members on the House Judiciary panel are still against pursuing the impeachment of the Homeland Security secretary. And House Republicans are starting to focus their efforts on pursing an impeachment inquiry of President Joe Biden, particularly since House Speaker Kevin McCarthy has warmed to the idea.

It's exceedingly rare for a Cabinet secretary to be impeached, something that has only happened once in US history when William Belknap, the secretary of war, was impeached by the House before being acquitted by the Senate in 1876.

In the impeachment articles that have been filed, Republicans have accused Mayorkas of undermining the operational control of the southern border, encouraging illegal immigration and lying to Congress that the border was secure -- all charges that the administration has dismissed.

On Wednesday, Republicans will likely grill Mayorkas on all those issues, even though there have been fewer border arrests in recent weeks. In June, for example, US Border Patrol arrested nearly 100,000 migrants along the US southern border, marking a decrease from May and marking the lowest monthly border encounters since February 2021, according to US Customs and Border Protection data.

But challenges remain for the administration as it escalates its feud with Gov. Greg Abbott over his operation on the Texas-Mexico border and as it faces a court ruling against a key immigration policy.

On Monday, the Justice Department filed a lawsuit against the state for installing floating barriers in the Rio Grande without authorization.

Border agents have historically worked closely with Texas National Guard and the Texas Department of Public Safety. But the latest steps taken by the state have made day-to-day operations more difficult. DPS, for example, made certain portions of the Texas-Mexico border more difficult to access, marking a departure from the coordination that previously existed between law enforcement.

Agents on the ground have also sent regular reports to CBP headquarters about what they've observed as Abbott's operation has been underway, a Homeland Security official told CNN.

And on Tuesday, a federal judge blocked Biden's controversial asylum policy, delivering a major blow to the administration, which has leaned on the measure to drive down border crossings. The judge put the ruling on hold for 14 days for a possible appeal.

A Justice Department spokesperson told CNN that the department plans to appeal.