He's not as maverick as he portrays himself to be. He takes some grand, well-reasoned and principled stands yet he ALWAYS fails to follow through? Many of his political views are deserving of legitimate respect on both sides of the political arena. He gives up on them too easy. He's more of a scavenger that way.
You can't openly denounce a demagogue like Trump (preelection) then throw all your political weight and fury to help that demagogue win the election because... you know... opportunism... and bitch about the sh!testorm and tsunami that Trump unleashes on you ... because Trump ... being a psychopathic, antiloyal (to turn a phrase) coward always returns political favors with an appropriate punishment.
We need to stop putting McCain up on a pedestal as long as McCain himself is loading the shotgun that Trump in return keeps shooting McCain in his face time and time again.
Either McCain takes Trump down (and he's politically strong enough to do it given the well earned credibility he has managed throughout his decades political career) or he can keep returning back to Trump and the Republican party like an abused, neglected and submissive dog while basically destroying his only chance to save his party and ultimately the country from any further political cancer that is Trump.