Republicans have mastered post-truth politics. They've realized that their rhetoric doesn't have to bear any connection to their policy agenda. They can go through different slogans, different rationales, different fights, depending on the political landscape of the moment. They need not feel bound by previous slogans, rationales, or fights. They've realized that policy is policy and politics is politics and they can push for the former while waging the latter battle on its own terms. The two have become entirely unmoored.
So it's not that they "moved right" on some policy spectrum when Obama took office. They just adopted a new political strategy, namely total, unremitting, hysterical oppositionalism.
I think they are both missing something. Its hard to know exactly what Obama's policy preferences are. Though I don't think it would be unfair to say that personally he is a little more liberal than he is as the president. Though I say that judging from his campaign and that could have certainly been political rhetoric and not everything he believes personally.
But the point is that Obama as a president appears to be a moderate Republican from the 90s because he has to get moderate Democrats in Congress, and especially the Senate, to support bills. I would wager that those moderate Democrats are the ones that more closely mirror moderate Republicans of the 90s. Obama just looks like he does because he is more concerned about governing than he is about waging ideological warfare from the oval office. And that's why many of us liberals are disappointed in many of his policies.
And while I agree with Roberts that the policy of Republicans at this moment is oppositionalism, even they won't take this to its extreme. If Obama came out tomorrow and said that he supports even further reducing taxes they wouldn't take the opposition to that policy just for the sake of being oppositional. If he came out and said he will vote for Paul Ryan's budget and he will tell Dems in Congress to pass it they won't all of the sudden jump off the Ryan ship. So at some point there is a liberal policy and a conservative policy. And while some instances like cap and trade seem to be completely about oppositionalism, there are limits to what policies each party will embrace. And perhaps the biggest limit on that is the size of the majorities in Congress.