The sad thing is, I could see wide swaths of the GOPe thinking this is a great idea.
If somehow the GOPe drafted Romney at the convention, the base would not turn out at all. The losses to the Republican party would be of 1964 or 1974 proportions. I would vote for a few local conservative candidates but that would be it.
If its a decision between Hillary and Trump many republicans view Hillary the lesser of the two evil. It is sad, but true. I could see the republican under vote (anti-Trump people) supporting a Romney third party run, not because they think Romney can win, but because they believe it would syphon enough republican support from Trump to cost him the Whitehouse.