So What's The Deal?
Americans tend to see Congress as a bunch of old, out-of-touch white men deep in the pockets of special interests. We don't agree on much these days, but we do agree on how much we hate the people we elected to office. In real life, the American government is protected by a system of checks and balances that don't allow any one branch (or person) to completely take over. But an efficiently run bipartisan commission doesn't readily lend itself to shootouts with M16s or badass one-liners.
Americans hate their congressmen because they are, by definition, members of a large body that have to compromise to get things done. We don't want limitations or compromise; we want them to deliver on their campaign promise of making Taco Bell the national religion. All the backchannel dealings and political doublespeak isn't very heroic. We want to see a hero make a grand speech before shooting an undead fascist reptilian in the neck, and we don't want to see it get held up in committee.