Republican Sen. John McCain is returning to Arizona after spending several days in a Maryland hospital recovering from side effects from chemotherapy treatment for brain cancer, CBS News has learned.

McCain left Washington Sunday and is heading back to his home state to spend the holidays with his family. He will not be on hand for the final vote on the GOP tax passage expected for early this week. It is unclear when McCain might return to Washington.

BREAKING: CBS News has learned Republican @SenJohnMcCain will not be on hand for the final vote on the GOP tax passage expected for early this week; he is returning home to Arizona after spending several days in a Maryland hospitalhttps://t.co/UAXiQkiqVM — David Begnaud (@DavidBegnaud) December 17, 2017

Despite a razor-thin margin needed to pass the measure, McCain’s presence will not likely be the determining factor in the vote. Two critical senators — Bob Corker of Tennessee and Marco Rubio of Florida — announced their support for the bill last week after initially saying they would oppose earlier versions. – READ MORE