Wallace/McGovern seems least likely.
Eh well Wallace was arguably the most anti-war (or perhaps rather, least pro-war) of the 3 candidates with his pledge to withdraw the troops from Vietnam if the war wasn't won within 90 days of taking office. Maybe one-issue voters who wanted us out of Vietnam and were willing to overlook the other views of a candidate, no matter how abhorrent, went Wallace-McGovern.
Maybe repentant racists?
People who voted for Wallace genuinely solely for his populist economic policies and then voted for the Prairie Populist McGovern?
Obviously there couldn't be too many of them since Wallace won many counties across the South, some by massive margins, but failed to win a single county outside the south, while Nixon '72 DOMINATED the South.
