...sometimes the choice is between bad and worse.
Excerpt from the link:
The world has by now largely forgotten Sendero Luminoso, or the Shining Path, but at the time (between 1980 and the capture of its leader, Abimael Guzmán, in 1992), it was the most sinister revolutionary movement in the world, as fanatical as the Islamists today. I went to the highland city of Ayacucho, where the movement started, at a time when it seemed far from impossible that Sendero would overthrow the odiously demagogic and contemptibly corrupt government of Alan García. If it did so, I had little doubt that the world would soon see a reenactment of the days of the Khmer Rouge, but on a much larger scale. It was a perfect lesson in politics: that the choice is not usually between the good and the bad, but the bad and the worse, in this case the far, far worse.
...
...When two years later I heard that Sendero’s founder and leader, Guzmán, had been captured, I felt a great relief for Peru, even though the president, Alberto Fujimori, turned out to have been grossly corrupt. He was only ordinarily bad, however; Guzmán was Pol Pot bad.
I remember what one Peruvian peasant said when asked why he had voted for Fujimori: “I voted for Fujimori because I didn’t know anything about him.” There are probably many worse reasons for voting for someone.
Link: The Choice Between Bad and Worse