For Trump, party unity is nice, but not necessary
Ahead of a private meeting Thursday with House Speaker Paul Ryan, Trump used several televised interviews that aired Sunday to knock Ryan and other influential Republicans, along with a nomination system he says is "totally rigged."
The New York billionaire seemed to be sending a message to party critics who are withholding support or planning to skip the convention.
Among the biggest questions ahead of Trump's private meeting with Ryan is whether Trump will call for Ryan's ouster as chairman at the Republican convention in Cleveland this July, if Ryan refuses to back him.
McCain, a Navy pilot shot down and held as a prisoner of war by the North Vietnamese for five years, said Trump owes military veterans an apology.
Sen. Jeff Flake, a Trump critic, said Republicans should figure out something fast because Trump's ability to win primary contests by relying on hardline policies such as banning Muslims from entering the United States might not translate into general election success against the Democrats.