Fundamentalists impose their beliefs on others through government. They are nutty and deny science. A lot of these fundamentalists are within the Republican Party that preaches "individual freedom". However, their hypocrisy shows when they want to take selected freedoms away from others in issues like abortion and gay rights. I hope the next generation is able to see this and get these looneys out of our government.
They want the government to endorse their religion, and make inroads on this frequently- see the nation-wide campaigns against gay marriage and the number of states that have (largely due to the Christian right's political campaigning) banned it in their constitutions. They want to push their religious myths into our science classrooms, further damaging our children's education at a time when science and mathematics education are both failing in America and vitally important to survival in the global economy.
They want to heavily restrict women's freedom based on their own personal opinions, trying to push ever more draconian abortion and contraception restrictions and denying children proper sex education in schools.
Religious fundamentalism is a menace- wherever it is found in large numbers, oppression follows.
If Fundamentalism becomes rampant in any democracy, the result will be a demand for religious law by the people. This is dangerous to democracy, since no large-scale religion really teaches that democratic freedom and authority are good things. (Some religions do teach this, but they are all minority religions.)
Most religions do not teach that freedom is anything but scary and sinful, and teach self-restraint and subjugation to a priest class.
Except that I have a lot to say. I've already been debating this issue, and if you want my opinion, you can check out what I've said in this debate: http://www.Debate.Org/debates/Church-and-State-should-remain-separate./1/ aside from that I really don't have anything else to say, but I have to fill 50 words. Mission accomplished.
In general, they dont have a whole lot of political power. The laws that are fundamentalist based are dying every day. More states are accepting gay marriage. Sodomy laws are gone. We have the guarantee of religious freedom. Masturbation, eating pork, immodest dress, rock and roll, and alcohol are still legal