He was a political coward, not a maverick. When he faced tough re-election campaigns, he quickly dropped his maverick credentials in the recycling bin and pandered to the party's base, then reneged on his promises to them (tightening immigration, securing the border, fiscally-conservative policies in Washington, and resisting the Obama presidency whenever possible). Even MSNBC's glowing exposé about him shortly after his passing was announced made no bones about his chameleon-like clothing changes on the campaign trail. In 2008, the mainstream media hated him because it suited their narrative; in light of his perplexing, brash and self-centered obstructionism to this administration, clearly borne of bitterness and jealousy at never achieving an office he once admitted thinking of daily after two consecutive losses (2000/2008), he's now their favorite folk hero. It shows you the paper-thin veneer behind which the left-wing media operates when it aggrandizes or destroys people based on the prevailing social breeze.
If you want to laugh, go look up that SNL episode of Fun with Real Audio where McCain reenacts the opening scene of Apocalypse Now in Bush's campaign trailer while then-candidate Bush nervously awaits him on the podium to give a speech to a crowd of his supporters. He ends up bashing his head bloody and screaming incoherently at having to do the unthinkable and support someone he clearly considered less than human.