Rick Santorum, that's why.
Well not only him, but the side of the GOP that he represents. The same politicians that decry Islam in government turn around and proclaim that the US is a Christian nation and that our government policies should be in line with those values. Opposition to birth control? Anti-abortion legislation? Opposition to gay marriage? All of these stem from the Christian values they promote. Why is wrong from Iran to be run by religious authority, but it is only right that the US be run by a fundamental God-fearing Christian? Now before someone starts to go off on be about the differences between Islam and Christianity, I want to point out that fundamentalism on either side provides for many of the same results. Islam created the Burqa. Christianity created Rush Limbaugh calling a woman a slut and prostitute for being in favor of birth control. Both result in male-dominated sexism, bigotry, and intolerance. Now, as a disclaimer, I am not trying to say all religion is evil, bigoted, or whatever. I am not here telling everyone to drop their beliefs and become atheist. I am simply trying to point out hypocrisy and show the danger of fundamentalism in any form. As a fun conclusion, I send you here.