No,  the democratic party hadn't become anti-Christian. America has become less Christian.
But relating the republican party to Christianity is a little hard to equate. What about trump is Christian? If 5 children by 3 different mother's, adultery, fraud, racism are Christian values, that's news to me. 
Just because the republican party claims they are "more Christian" doesn't mean they are. 
The democratic party's whole platform is helping the working class, helping the poor, feeding the hungry, etc. That's Christian values in deed not just in word.