"Campus activists who try to prevent free speech often through violence are a vocal minority who generate a great deal of publicity which harms their cause."
You mean leftist campus activists right? Because campus conservative activists don't engage in violent intimidation techniques to try and prevent free speech.
"... before moderate ideas are disregarded."
And what exactly does your final sentence mean? That the violence of left-wing students should be ignored because you see other kinds of bad things going on elsewhere?