@OmSigDAVID,
If the natural tendency of a politician is to do what is "right" for his constituency, then term limits would not be good.
But if the natural tendency of a politician is simply to get re-elected by whatever means possible, then they would find themselves beholden to special interest groups who fund their campaigns through covert mechanisms.
The natural selection process that occurs in politics favors those politicians who's primary goal is to get re-elected, resulting in the government the US currently has, whereby most politicians are beholden to their source of campaign funding.
I have no proposed solution to the problem. Term limits are a double-edged sword. So long as political success is driven by effective marketing (money), which seems inevitable in our media driven society, the problem will remain.