Trump probably thinks he’s discouraging people from attacking him by insulting them — in crude but not uninformed fashion — when they do. But he’s having the opposite effect, I think. Getting attacked by Trump is what you want right now. It’s surely the best thing that’s happened to John McCain in a while. RIck Perry too — Perry may make the debates because Trump questioned his IQ. It’s the logic of trolling, writ large.  … Trump’s fire would only be suppressive if his putdowns were so devastating the damage outweighted the publicity. But they aren’t. His best shot was probably the one against Mitt Romney — “He lost an election that should have easily been won against Obama” — because it put in words what most Republicans actually think. Even so, it was a net plus for Romney, I suspect. …