Doesn't make Portman a terrible person, and in fact, considering the CPAC clown show is in full swing this weekend, it may push him away from the mossback factions of the GOP. It may also, one hopes, force the party to finally push said mossbacks back out on the margins, where they belonged in the first place. Better late than never, they are finally getting the message that maybe their in-house weirdos, with their tragic obsessions and oddball diagnoses of buttfucking and ladyparts, are doing the brand way more harm than good.
The 'pubs are going through the usual post-electoral "why we lost" kabuki, figuring that if they present a less bloody maw to the minority voters they desperately need to retain any relevance (assuming they at some point decide to stop disenfranchising them, that is), they have a chance in 2016. They are only slightly behind the Democrats in that regard, though Obama does deserve credit for at least announcing his "evolution" on his position months before the election, plenty of time for the obsessives to turn to the usual mortifications of the flesh.
But Portman deserves no credit for his metamorphosis -- he "changed" because it became an issue that mattered to someone he cares about, which is as chickenshit as it gets. The ability to empathize with people, in the abstract sense, as opposed to specific persons whose situations we care about as friends or family members, is generally considered to be a primary difference between adults and children.
The Democrats, with their grueling, stolid incrementalism, are not a huge amount better in this regard, nor in terms of empathizing with the plight of the economically disaffected, at least in a way that actually makes a difference in their lives. Remember when Bill Clinton swore up and down that American workers "displaced" by NAFTA and GATT would be retrained, so that the American workforce could remain competitive and innovative and all that? Right. The economy got Rubinized, before it got Grammed, and the "retraining" was turned over to usurers and profiteers, dangling the sweet promise of credentialism in exchange for a decade or two of debt peonage.
That would be the same Bill Clinton who voted for the "Defense of Marriage Act" an Orwellian name for a legislative turd if ever there were one, because Compromise Is Necessary and he needed to Get Things Done. Since enabling the banksters with the repeal of Glass-Steagall, Clinton has gone on to make millions on the rubber-chicken circuit, and if his hagiographers have any say about it, will probably end up on the dime or Mount Rushmore at some point.
Whenever a politician claims to be doing something or adopting a position on grounds of moral principle, you can be certain that if that entered into the equation at any point, it was only after virtually all risk was eliminated. That's not brave or principled, nor does it require much in the way of empathy. It's simply an ethical convenience.