left students mutiple times forced right speakers to cancel speeches, not through very peaceful way. it is well reported.
as for violence against righties, i don't have time or energy to check, but use common sense one can almost be sure of some happened. white supremacists are so offensive that violent reaction, epsecially from blacks, are certainly to be expected.
i remeber one nbr interview about the turmoil in VA, on eleft activist said "if the ogvenment don't stop them (white supermacist), we will", i wonder how he was going to "stop" it?