text: Yes, voting for a KKK member because you agree with Jim Crow laws might put you in a state of mortal sin.  I don't think that voting for Hillary Clinton does and I think that certain US bishops have harmed the Catholic Church by using Communion as a weapon against one of the two US political parties.  It makes it seem like the Vatican is trying to control US politics.  (Which is what JFK had to deal with in 1960.)