WASHINGTON — Sen. John McCain left the nation’s capital Sunday to spend Christmas in Arizona with his family as he battles brain cancer, giving his Republican Party one less vote as it is expected this week to attempt to push through a contentious tax bill along party lines.President Donald Trump told reporters Sunday that McCain, R-Ariz., and his wife, Cindy McCain, have “headed back [to Arizona], but I understand he’ll come if we ever needed his help, which hopefully we won’t.” He added: “But the word is John will come back if we need his vote.