>they were able to gain power and influence due to the ambivalence and apathy of (and tolerance by) the masses.

Yes, this is the only example I could really think of, but it isn't a good, concrete example by the simple facts that Hitler was never elected as chancellor and the Nazi party never held a majority in the Reichstag. In other words, tolerance didn't give them power, the took power. They also did a lot of things other than propose ideas to get into power.

I don't want the idea of allowing people to present and hold distasteful thoughts confused with being allowed commit crimes (including but not limited to assault, murder, carrying an illegal firearm, inciting a riot, etc).