If you don't have a record to run on, then you paint your opponent as someone people should run from.
Note the lack of cheering or applause after he said that phrase. I think it shocked them, because it was exactly what he was in the process of doing in the speech -- and it describes his campaign perfectly!
I wonder if Hillary messed with the script! :)
Without a doubt, this was the single dumbest, most inexplicable line in the whole speech.
150 or so days as a Senator is NOT a record to run on.