Not sure how he thinks that, but if someone shot through one of his campaign offices, that is despicable too. No excuse. No evidence at this point that it was political or intentional, but if it was an unhinged liberal then it was wrong. Period.
That said, one key difference is that I am not aware of any Democratic leaders out there making jokes about shooting Republicans or suggesting that we should take violent actions against Republicans. Help me out if I am wrong here.