Steve Scalise returned to the Capitol after cancer treatment and noted that the votes are tight

Rep. Steve Scalise of Louisiana, the majority leader, returned to the Capitol on Tuesday after a six-week absence during which he received a stem cell transplant as part of his treatment for blood cancer.

His Republican colleagues in the House of Representatives were counting on him to return to oust Homeland Security Secretary Alejandro N. Mayorkas after a humiliating setback last week when three Republicans joined all Democrats in rejecting the charges, leaving the Republican Party just one vote short. majority.

“I'm back,” a smiling Mr. Scalise, mask in hand, told a Fox News reporter as he reentered the Capitol on Tuesday afternoon. Mr. Scalise said he felt “great” and expressed confidence that the impeachment vote would go ahead as planned.

“It's really exciting to be back in person,” he said. “I heard the votes are tight; Every vote will matter here.”

Last week, after the stunning defeat of the first impeachment attempt, Republican leaders quickly said they would try again as soon as Scalise could return, possibly even the next day. That raised questions about whether the majority leader could put his health at grave risk to help Republicans press their case against Mr. Mayorkas, who will almost certainly die in the Democratic-led Senate.

But Mr. Scalise said on Tuesday that after weeks of isolation for an autologous stem cell transplant, he had been cleared by his doctors to travel.

During the process, he said, “they don't actually give you an immunity system. Your system is really not capable of fighting diseases.” But Mr. Scalise said his doctors told him his white blood cell count was high enough to be cleared to “be around people again.” Mr. Scalise said he planned to resume his full in-person schedule.

He stuck with it on Tuesday its annual tradition of delivering king cakes to his colleagues and Capitol Police officers to celebrate Mardi Gras.

Mr. Scalise's office said in a statement last week that he was in full remission.

Mr. Scalise, the No. 2 Republican in the House of Representatives, announced in August that he had been diagnosed with a rare form of blood cancer. He continued to work while undergoing treatment, including an aggressive form of chemotherapy.

Republicans in the House of Representatives eager to move forward with Mr. Mayorkas' ouster cheered his return on Tuesday.

Representative Marjorie Taylor Greene, a Georgia Republican who has led the charge against Mr. Mayorkas, said on social media that Mr. Scalise had “put cancer into remission” and that the Louisiana lawmaker returned to #impeachmayorkas on Fat Tuesday. During the race for the presidency in October, Ms. Greene had raised concerns about Mr. Scalise's diagnosis as she opposed his bid for the gavel.

His allies in Congress said Mr. Scalise looked and sounded great, and that they trusted he would not jeopardize his health by rushing back to Capitol Hill because his party so desperately needed his vote.

“While Steve Scalise will always put his country ahead of his own health concerns, I trust that he will make his own decisions and that he does not owe any of us an explanation,” said Rep. Lance Gooden, Republican of Texas. “We're happy he's back.”