Why David Hume Defended the Rights of “Seditious Bigots”

Some can't imagine a downside to punching Nazis, or otherwise obstructing their spewing of hate. How could the world not be a happier and sunnier place after the forcible removal of such a spiritual pollutant? In the face of such an obvious potential pragmatic benefit to society, isn't concern for the rights of Nazis so much fussy, abstract philosophizing?

David Hume shed some light on this problem, explaining way back in 1738 the pragmatic utility and public interest in granting even "a seditious bigot" his rights.