Rob Portman’s position reversal to support gay marriage creates one of the biggest political and cultural Rorschach tests of the year for the in-search-of-its-new-self Republican Party. (see Roll Call news story.) From the floor of the CPAC convention to the bar at the Capitol Hill Club to the offices of the Log Cabin Republicans, an enormous range of questions are being pondered now that the Ohio senator has revealed — on CNN last night and in the Columbus Dispatch this morning — that he changed his mind about one of the defining social issues of our time because one of his sons told him he is gay. The story is undeniably important because it makes Portman, already one of the most serious and respected voices in the party on fiscal policy, the only current GOP senator publicly embrace same-sex marriage. But why? (more…)