And what’s the percentage of nominal Christians who vote that way too?
When you say, "that way", I'm assuming you mean "vote democrat". Please let me know if I'm wrong in my assumption.
A report by Pew published in its U.S. Politics & Policy section found that while 73% of Democrat voters were Christian in 2008, by 2019 the percentage had dropped to 52%.
Why so-called Christians vote for a party whose policies are blatantly anti-Christian, immoral and sinful can be answered with the acronym CINO - Christians in name only.