Shortly after being diagnosed with brain cancer, Sen. John McCain (R-AZ) flew back to Washington, DC, on Tuesday and voted to advance Republicans’ plan to repeal Obamacare.

Then he gave a speech from the Senate floor in which he criticized the Senate for not following “regular order,” urged senators to consider themselves the equals of the president, and said he wouldn’t vote for the health care bill as it stands now. (He did not say which of the several health care bills under consideration he opposed.)

McCain’s return, greeted by applause and an ovation by his Senate colleagues, proved crucial for preventing the immediate defeat of Republicans’ health care bill — which the Congressional Budget Office has estimated would cost tens of millions of people their health insurance.

Then in his speech, McCain announced his opposition to the bill “as it is today” and castigated the process of a bill drafted in secret. He also admitted his own flaws as a US senator. “Sometimes I've wanted to win more for the sake of winning than to achieve a contested policy,” he said.

As Vox’s Dylan Scott has explained, Majority Leader Mitch McConnell needed 50 of 52 Republican senators to approve the motion to proceed on a health care debate. BuzzFeed’s Alexis Levinson captured a photo of McCain giving reporters a thumbs-up as he headed into the Senate chamber for the crucial vote: