It is very possible that Trump will be challenged in the primaries by someone who takes a very hard line on abortion. How will he respond?
This will be a very difficult decision for him, because his natural (practically only) move is to pander to the base. He has shown some awareness, however, that an extreme position on abortion is likely to damage his interests in the general election. My guess is that he will abandon the base on this issue alone and propose some sort of compromise.