That seems a reasonable explanation to me. When it comes to moral issues like abortion, it’s something he probably never thought about before.
I’m still deciding whether that’s a really bad thing or a thing that could actually be okay. If he’s got no conviction about it, he wont make it a priority to fight to end abortion. However, it also probably means that he’s willing to stick to the party line and (at the very least) not do anything to make it worse.
We probably do hold politicians up to an unreasonable standard when it comes to changing their minds. It seems this “flip flopping” on abortion comes up for every Republican nominee. The same thing was said about Romney and McCain. It does make it easy to be suspicious when the party nominee always seems to have become increasingly pro-life only recently. I’m still deciding whether it’s better to take the pro-life lip service over the overtly pro-abortion candidate or whether it will ever come to a point where we need to insist that lip service is not enough, even if it means the GOP loses that election.