To the charge that term limits are undemocratic, the answer, in Palinspeak, is, "You betcha." That is, they are as undemocratic as, say, the First Amendment, which begins with the most lovely five words in the English language -- "Congress shall make no law." The amendment lists some things that the people's elected representatives cannot do even if the people want them done, such as abridge freedom of speech or legislate the establishment of religion.
The undemocratic aspect of term limits has never bothered me. The average voter often chooses the incumbent for a variety of reasons: the incumbent has more money to buy political ads, ignorance on the part of the voter, stupidity on the part of the voter, comfort with the devil you know, or simple laziness. Anyway, I know for a fact that the 535 people in congress at any given time are not the best 535 people that could be in those jobs. Yet, most of them stay in place because of the aforementioned factors. So, let's stop hailing what the people want as always the best. It's often the best. More often than any other form of government by far, but it is not always. Sometimes we need some new blood just for the sake of new blood. Not to mention the possibility that long-serving civil servants have a tendency to create little fiefdoms for their own benefit at the expense of the people.