Saying 45% of your party's members support same-sex marriage in 2016 is about as bold as saying 45% of your party's members support desegregation of public facilities in 1968. It means you are profoundly on the wrong side of history and general decency.
And if 45% of Republicans support same-sex marriage, why are there only like two Republicans in the House who do?
Bit there is the Pub nominee, who does.
Which is why he chose Pence, who he will put in charge of most Presidential decisions? Please.
That choice was forced on him. He wanted Kasich, but Kasich wouldn't budge, probably because he still thinks Trump is going to lose.
Trump needed someone to shore up the Establishment and conservative support.
However, his real opinion on the subject is well known.