It always strikes me as odd that some can't realize the reality of the situation where many people are participatory in the government (ie, the House and Senate) and how many corporations can use their capital to influence these politicians. The benefit of the republic system we have is that, in theory, we can elect people who seem to represent out interests and replace them when they fall out of representing the peoples interests. It's not a perfect system, but none are, and it tends to work out at least reasonably well with the tension created by the two parties. Yes, the Republicans and Democrats both pander to their donors, but at least the tend to have different, conflicting. donors, and the odd politician that actually cares about the people..
I'm not sure where the religious zealot view comes from. As an American (and you, going by your post, are not) I can say the the idea of "crazed religous zealots" is highly overblown by the media and anyone who acts in that manner in the Senate or House are generally fringe candidates and make up the vast minority of the governmental population.