Bill Maher on McCain: Someone in a health crisis should see how wrong repealing ObamaCare would be

HBO host Bill Maher is questioning why Sen. John McCainJohn Sidney McCainGOP lambasts Trump over performance in Helsinki Trump stuns the world at Putin summit NY Daily News cover following Helsinki summit shows Trump shooting Uncle Sam MORE (R-Ariz.) is heading back to Washington after being diagnosed with brain cancer to vote on an ObamaCare repeal bill that will "leave other sick ppl without care."

"Surely someone currently in a health crisis can see how wrong it wld be to repeal ACA and leave other sick ppl without care," Maher tweeted Tuesday morning, hours before McCain is expected to arrive at the Capitol for the vote.

The 80-year-old lawmaker underwent an emergency craniotomy last week to remove a blood clot above his left eye. He was later diagnosed with a glioblastoma, an aggressive form of cancer.

McCain is returning to Capitol Hill to vote on the ObamaCare repeal bill, his office announced Monday.

“Senator McCain looks forward to returning to the United States Senate tomorrow to continue working on important legislation, including health care reform, the National Defense Authorization Act, and new sanctions on Russia, Iran and North Korea," McCain's office said.

Republicans are expected to vote to take up the House-passed healthcare bill Tuesday afternoon. Senate Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellGOP lambasts Trump over performance in Helsinki Overnight Defense: Washington reeling from Trump, Putin press conference Feehery: The long game MORE (R-Ky.) will need 50 of the Senate's 52 Republicans to vote for the motion to proceed.

Without McCain, McConnell could only afford to lose one GOP senator on the initial hurdle. With McCain back, however, he can lose two GOP senators and still let Vice President Pence break a tie.