People get way too worked up over the presidential contest.

The President has little actual power. It's the legislators that can actually do things. The President gets to appoint Supreme Court Justices, but they don't die off too fast. This means the political pendulum tends to swing back and forth very slowly.

The actual mudslinging campaign is kind of ugly on the surface, but even the most annoying of candidates contributes to the process. The campaign process highlights the fact that our country has a kick @#%$ bill of rights, and specifically all these good/bad/interesting/lame issues are discussed publicly. A public discussion occurs and these issues are brought to the public's attention. It's very rare that any campaign promise is instituted into law in the exact manner that it was originally put forth. In the end, the legislators end up with some sort of compromise and the country moves along. The extremist ideas tend to get weeded out, thankfully.