I'm being a little nice with WV to McGovern but I think that's the best he could do. McGovern being so liberal would do decently with that base and the voting hippies but Wallace running would kill whatever hope the Dems had of serious gains. If he'd stay a little from the race card and focus on appealing to the moderate and more conservative Dems he would have done a lot better. He would have won the majority of the south minus Florida, Texas, and Virginia.
Romney would pretty much have it in the bag. He would have to campaign still but I don't see him worrying much. I see him doing a Nixon esque style when it comes to angry Americans and those who hate the chaos. The Bush Sr pick would be smart for congressional reasons among other things. I see Nixon endorsing him here possibly. He would get the main Rep base and maybe a good amount of disillusioned Democrats.