Apologies for my error. In my experience, evangelical Christians tend to talk about Christianity as though all denominations and sects share their social beliefs. Christianity is so much bigger than that. Catholics, Presbyterians, Methodists, Mormons, non-denominational, Baptists, many Unitarians, UCC - all Christians. And a massive portion of them are opposed to the current administration.
Pence has been waging a war of policy against the LGBT for his entire political career. This is not a tenet of Christianity. It is specific to his personal brand of Christianity, that approves of using government to remove dignity from people that aren't in line with his narrow beliefs. In addition to this, he's on board with a wide variety of Trump's more oppressive policies.
The reason no one (on the Left) wants President Pence is that he's an effective politician, unlike the current president. He's truly terrifying.