Chicago Mayor Daley and his police force made the mistakes with the protestors, much of the media coverage of the police riots falsely made it look like it was happening right outside the convention site.
Well, anointing the VP Humphrey as the new candidate, in a process that alienated a lot of the dem's base was a big mistake in retrospect.
I won't pretend to know the history well enough to know if there was any workable approach then, but the convention process in 1968 definitely didn't work to produce a candidate Dems were excited about at the end of it, the turnout was low and Humphrey lost in a landslide.
Also, I think some of it was happening right outside the convention site - Dan Rather was famously manhandled on national television by security guards while trying to interview someone leaving the convention.
Chicago Mayor Daley and his police force made the mistakes with the protestors, much of the media coverage of the police riots falsely made it look like it was happening right outside the convention site.