LOS ANGELES (TheWrap.com) – Mitt Romney had better ditch that trip to Poland and head back to the United States posthaste to shore up his teetering adult film star base. The presumptive Republican nominee just lost Ron Jeremy's endorsement, and with it the support of millions of Americans who turn to the porn legend for political guidance. Jeremy, whose more than 2,000 adult film credits clearly make him an expert on presidential politics and the American electorate, told the Boston Herald this week that he will be casting his vote for Barack Obama. …