As hatred for the racist rose, so did the racist's hatred. Now they really had something to fight against. Hatred became a national issue. Two separate groups of people were hating each other with equal zeal. So, we have the First Amendment.
People embrace it.
If someone feels that their rights have been taken from them, they become pretty darn irate. It becomes a very major deal, and the issue, which has now consumed them, becomes a large part of their social agenda. As was earlier said, education is a better solution. This is why. I believe there is a better chance of someone changing their actions, and their minds, when they see what their actions have wrought.