House GOP leaders are closely watching a few Republican lawmakers ahead of their expected vote on whether to impeach Homeland Security Secretary Alejandro Mayorkas next week.

With just a razor-thin majority and all Democrats likely to oppose the measure, Republicans will have to be in near lock-step to pass what would be a historic vote. A Cabinet official has not been impeached since 1876.

Rep. Ken Buck, R-Colo., told reporters on Thursday morning that he is a “solid” no on impeaching Mayorkas.

He criticized the Biden official for his handling of the southern border crisis, but said, “The people that I’m talking to on the outside, the constitutional experts, former members agree that this just isn’t an impeachable offense.”

At least four other Republicans are still undecided, at least publicly.

The office of Rep. David Joyce, R-Ohio, leader of the moderate Republican Governance Group, told Fox News Digital on Friday that he “has met with Chairman Green and is reviewing the material that they have provided.”

House Financial Services Chair Patrick McHenry, R-N.C., has not told reporters how he would vote. Reps. Dan Newhouse, R-Wash., and Tom McClintock, R-Calif., also declined to say which way they were leaning earlier this week.

Fox News Digital reached out to McHenry, Newhouse and McClintock’s offices for an update but did not immediately hear back.

House Speaker Mike Johnson, R-La., has been dealing with one of the thinnest House majorities in history over the last several weeks. With absences on the GOP side and the departures of three former lawmakers, Johnson has been walking a tightrope of just a two-seat majority.

However, he got some breathing room recently with longtime Democratic Rep. Brian Higgins, D-N.Y., resigning, effective Friday.

Majority Leader Steve Scalise, R-La., who was receiving treatment linked to his cancer diagnosis, and Rep. Hal Rogers, R-Ky., who has been recovering from a car accident, are expected back in the House soon as well.

It would be a massive blow to the House GOP’s emphasis on the border crisis if the Mayorkas impeachment were to fail in the House.

House Republicans are pushing to impeach Mayorkas over accusations of willfully disregarding the law to allow the migrant crisis to foment.

The effort has received support from the vast majority of House Republicans. Rep. Don Bacon, R-Neb., a key moderate who was also on the fence about impeaching the Cabinet secretary, told reporters earlier this week that he’d back it as well.

“I intend to,” Bacon said when asked about it on Tuesday. “Because we have a disaster at the border. And I would say there’s so many laws on the books that he could enact or enforce, and he does not.”