Lech Wałęsa
Unfortunately, after he became the president of Poland, he turned out to be a bit dumb (with his famous sayings, like "We will lower the prices by 50, or even 100 percent" or "I am for or even against").
Some people like him and vote for him when they got a chance, yet his popularity dropped from 80-90% to something like 2% in a matter of a few years.
My opinion would be, that he served his purpose as a revolutionist, yet nowadays he can't do much in the world of politics - after all, he's not a politician.