Ake said back up there ^

" I just don't understand why these things are linked to Evangelical Christianity."

Because at least 4 of the candidates, Cruz, Huckabee, Carson & Fiorina... as well as Rick Santorum, who has dropped out.... have said as much, and have actively courted Evangelical Christian votes by asserting their faith as their driving force.
Several others have reaffirmed 'almost' those views, but in less obvious ways.

*IF* someone bases their political decisions on their religious beliefs, they WILL inevitably try to repress the views of those who hold other religious views - or none at all.

John Kennedy was Catholic, but he managed to separate his religion from his office.... like the Constitution says. Obama is a Christian, but he does not insert his faith into decisions.

There are more examples on both sides