John Cougar Mellencamp’s combative liberalism has long been an unexpected plot twist for casual fans, politicians, and country music stars who’ve misinterpreted his populist lyrics as base expressions of American chest-beating. Today, he’s been met with some version of “How about you stick to music?” for so long that commenting is restricted on many of his social media accounts. Article continues after advertisement Amid the Reagan presidency and throughout the subsequent decades, Mellencamp’s antiracist, pro-farmer, anti-capitalist diatribes were tantamount to a bag full of hornets: intimidating in principle, and punishing when released. Mellencamp has regularly reminded Americans, through a torrent of fucks, that musicians also participate in the political process. Before he became a vocal ally of leftist causes, however, the singer reached a do-or-die crossroads.…