More on the subject of ideology.
Ideological commitments can change, but only for ideological reasons. For instance, one might return to "first principles" and come to the realization that they had been misapplied in a specific case.
But if the mere passage of time is all it takes to change one's mind, that's fine, but it means that the original opposition wasn't ideological.
Here's Kevin Drum on the changing poll numbers surrounding the ACA:
However, attitudes have already softened in one key area: repeal. In December, sentiment for keeping the law was slim: keeping and improving Obamacare beat out repeal by only 43 to 42 percent. Today, Obamacare commands substantial support, 58 to 35 percent. The public may still harbor some doubts, but they're increasingly tired of the debate and accept that the answer to Obamacare's problems is to improve it, not to burn it to the ground.