Klein gives Eagleton too much credit—McGovern’s candidacy was doomed even before then. The only Democrat who might have given Nixon a run for his money was Muskie, and I suspect a Nixon vs. Muskie race would have been more like GHWB vs. Dukakis than like GWB vs. Kerry.
My thoughts exactly when I read that line. Klein has either a poor understanding of the political realities of 1972 or was too deep in a hallucinogenic fog to even remember. When a candidate loses every state, save one, there was a larger problem than choosing a poor VP running mate.