First, let's not confuse the Constitutional right. Everyone has the right to be batshit crazy as long as the beliefs don't infringe other rights, eg, a right to execute adulters.
Second, it matters to me when people like Bush put their decision-making in god's hands and say that they make their decisions after talking to god. And it matters to me that Obama went happily to a Church with a seemingly bona fide lunatic at its head for a decade.
So it does matter to me. If you have some little box where you go to talk to god, I can get over it as long as you are basing your day-to-day actions on some rational and reasoned belief system. Lincoln seemed to work in that framework. Today's politicians, however, can't get elected without proving that they go to church diligently and believe in god (preferably the Christian one). This Jesus litmus test for politicians is abhorrent and the lack of tolerance for non-believers is still a widespread fact of life--while the secularists disdain for religion remains a quaint little point of interest.