I think it has to do with that tired old strategy of theirs. If the president is for X, then the republicans must therefore be against X, which the DUmmies can then say, "See? Those eeeevil republicans don't want you to have X. They want you to suffer and die!" or some such nonsense. Throw in the typical "Y-ist" and "anti-X" name-calling and a generous portion of fearmongering, and you've got yourself a campaign for the next election.