Forget about separation of religion from politics.
Well the research shows that nearly 80% of Americans believe in biblical account of creation, versus only 15% in evolution.
Now, if you don't see how deeply sad and troubling it is, don't despair, you are not alone, 8 out of 10 people will not.
Politicans being glorified, yet the still sleazy snake oil salesmen, would never dare to oppose 80% of the public opinion -- even if they believed otherwise -- sadly, most of them don't.
Then again, there is a bright side. In feudal Japan there was about 7% of educated class, in medival Europe even less, so 15% in USA is not bad.
I am sure that with another 20 years of teaching evolution and ecology in every school (they did teach me both 20 years ago in Poland), we can get to, well maybe 20%, that is if some RELIGIOUS WAR will not wipe us out first.