The question now is how the alt-right will process the backlash, and an early indicator will be seen in Saturday’s marches and rallies.

Terrorism is a double-edged sword. While it can help mobilize the most radical segments of an extremist movement, it simultaneously alienates the least radical, including people who are loosely supportive of an extremist movement, or tolerant or dismissive of its rhetorical excesses.

The risk that terrorism entails for extremists was clear after the Oklahoma City bombing, when the anti-government Patriot movement rapidly went from boom to bust, as adherents melted away—some due to fear of a government crackdown, others in genuine moral dismay over the attack, which killed 19 children and injured many more. The Patriot movement has since recovered from these setbacks, but the process took years, and McVeigh is still a controversial figure for many adherents.