Nixon led George Wallace in the South by 9 points in a hypothetical 1972 poll

[Some of My Best Friends Are Gay]

Based on that, I would guess this would have been the map if that poll had been accurate and Wallace was the nominee:

Nixon hits 60% in every non-Southern state save for Michigan, Massachusetts, and Rhode Island. Wallace only wins two states - Mississippi (by a margin of something like 56-44) and his home state of Alabama (by a margin of something like 65-35). Nixon wins Louisiana with a plurality but obtains a majority of the vote in every other Southern state. New England and the West Coast swing massively towards Nixon as compared to the actual 1972 results, while the South swings massively towards Wallace. I wasn't sure about DC but since this is a two-way match-up without a major third party, I assumed it would vote for Nixon as Nixon definitely would have won the black vote vs. Wallace if there was no left-wing third party. overall Nixon wins the Electoral College 522 to 16 and the Popular Vote by a margin of something like 64-36.

[Some of My Best Friends Are Gay]

I imagine you would have actually gotten a pretty similar county split to Reagan/Carter in 1980, as uncomfortable as that is for the "Dixiecrats were the first to switch to the GOP" narrative.

There would have been some major differences as compared to 1980. Nixon would have done way better with black voters than Reagan and much worse with Deep South whites, even compared to Carter's very decent showing with that group. Nixon also would have done a lot better than Reagan in New England.

[Some of My Best Friends Are Gay]

I think in a realistic what if on Wallace getting the nomination, he would have gotten Alabama, Mississippi, Arkansas, Georgia, Lousiana, and South Carolina. I think he would have done much better than McGovern electorally, but worse elsewhere. Ironically, I think electorally, he was the democrats best bet in 1972, but in the popular vote, he might have been the worst. So depending on which end you are looking at, he would have represented two ends of the spectrum

It's possible Wallace could have swept the Deep South, but if the poll OP linked was anywhere close to being accurate, he most likely would have won Mississippi and Alabama and absolutely nothing else.

[Some of My Best Friends Are Gay]

I imagine you would have actually gotten a pretty similar county split to Reagan/Carter in 1980, as uncomfortable as that is for the "Dixiecrats were the first to switch to the GOP" narrative.

Nixon probably does better in the rural south than Reagan did and worse in the Suburbs . Reagan strength in the Suburbs was more than really any candidate in the post war era but he struggled in rural and working class areas (except in the west) compared to Nixon

So you're basically admitting the Southern Suburbs were racist then.

[Some of My Best Friends Are Gay]

I imagine you would have actually gotten a pretty similar county split to Reagan/Carter in 1980, as uncomfortable as that is for the "Dixiecrats were the first to switch to the GOP" narrative.

Nixon probably does better in the rural south than Reagan did and worse in the Suburbs . Reagan strength in the Suburbs was more than really any candidate in the post war era but he struggled in rural and working class areas (except in the west) compared to Nixon

So you're basically admitting the Southern Suburbs were racist then.

Nixon was more racist comparatively than Reagan

That's true, but I don't see why Wallace would do very well in the suburbs, except for in Alabama due to home state advantage, and even then he would do worse in suburbs in AL than he would in rural areas.

[Some of My Best Friends Are Gay]

Why didn’t Wallace win South Carolina in 1968?

Because of the suburbs going for Nixon.

[Some of My Best Friends Are Gay]

Why didn’t Wallace win South Carolina in 1968?

Because of the suburbs going for Nixon.

Were there more suburbs in SC than in the Wallace states or did the SC suburbs go for Nixon more than the Wallace state suburbs did? If the latter, why?

There weren't really more suburbs in South Carolina than in the states Wallace won, but Wallace lost them by noticeably more than he did in other Southern states. he also didn't overwhelmingly win the rural areas like he did in the rest of the Deep South, only cracking 50% in two counties I believe. there was also more vote splitting between Wallace and Humphrey, with Humphrey doing better at the county level than in the rest of the Deep South, almost entirely because of black support and vote splitting of course.