I heard Rush Limbaugh say this the other day and it is true. Pres. Obama stated in the pass that he was not for gay marriage and says his thinking has evolved and he is now supports it. Mitt Romney was okay with abortion and now he is against it, but I have already heard and read pundits calling him an abortion flip-flopper. Well anyway, many think Pres. Obama was pro gay marriage all along ( such as one of his supporters in my family), but communicated the opposite, because it was not politically expedient. And yes, I know that the politically expedient argument can be applied to Mitt Romney changing his mind on abortion.
I am a little reluctant to call people flip-floppers when they truly have a change of mind/heart, because of a few of my own changes in thoughts/beliefs, especially when I went from Democrat liberal to Republican conservative.