WASHINGTON (AP) — President Donald Trump urged Republicans to “step up to the plate” for Tuesday’s crucial Senate vote on their bill eviscerating much of the Obama health care law. The stage was set for high drama, with Sen. John McCain returning to the Capitol to cast his first vote since being diagnosed with brain cancer.

No stranger to heroic episodes, the Navy pilot who persevered through five years of captivity during the Vietnam War announced through his office that he would be back in Washington for the critical roll call on beginning debate on the legislation. The 80-year-old has been at home in Arizona since he revealed last week that he’s undergoing treatment for brain cancer, but a statement said he “looks forward” to returning for work on health care and other legislation.

Senate Majority Leader Mitch McConnell, R-Ky., scheduled the initial health care vote for Tuesday. It seemed unlikely Republicans would bring McCain cross country if they didn’t think his vote would make a difference, and his mere presence could make it harder for wavering Republicans to cast a vote against even considering the bill.

Democrats uniformly oppose the effort to tear down Obama’s signature legislative achievement. Republicans control the chamber 52-48, meaning they can afford to lose just two Republicans with McCain around and only one in his absence. Vice President Mike Pence would cast a tie-breaking vote.

Trump kept up the pressure on GOP lawmakers, tweeting that “After 7 years of talking, we will soon see whether or not Republicans are willing to step up to the plate!” He added: “ObamaCare is torturing the American People. The Democrats have fooled the people long enough. Repeal or Repeal & Replace! I have pen in hand.” di

At least a dozen GOP senators have openly said they oppose or criticized McConnell’s legislation, which he’s revised as he’s hunted Republican support. While it had long seemed headed toward defeat, Republicans Monday began showing glimmers of optimism.

“My mandate from the people of Kentucky is to vote yes, and I certainly intend to do so,” McConnell said Monday in what seemed an implicit reminder to his Republican colleagues that they’ve done the same.