I mean look at how badly McGovern did in the South (not arguing WV is southern) in general despite the fact that it was still largely Democratic below the presidential level back then. Look at how badly Goldwater did in ancestrally Republican areas. There weren't floors like there are now.
This - it also had to do with Nixon making inroads with union workers and organised labour (IIRC a major union - the AFL-CIO, I believe - refused to endorse McGovern like it had with previous Democrats, and unlike for Goldwater or for Nixon in 1960 or 1968, many unionised workers - turned off by McGovern's progressivism - went for Nixon in 1972). Also want to point out how Southeast OK, which was also 'ancestrally blue' and quite Democratic in the 1960s/1970s, voted overwhelmingly for Nixon (by a bigger margin than Southern WV - every county in OK gave Nixon north of 60%, whereas McGovern still won a county in southern WV, and broke 40% in the other Southern WV counties).
