Nixon won election in 1968 by appealing to the "silent majority" in a year of total chaos, that many said felt like the precursor to Revolution. And there were, in fact, many leftist groups calling for Revolution at the time.
1968, the year of Nixon's first Presidential election victory over Hubert Humphrey had these components:
IN 1968 Nixon presented himself as the candidate of Stability, and it turned out that's what a lot of voters wanted. The alternative seemed to be turning the country over to a party that was itself a big part of the problem.
The Democrats chances were also harmed by the 3rd party run of Segregationist George Wallace, who won 5 states in the South. (The last 3rd party candidate to win electoral votes).
By 1972 things had calmed down a lot, and while it wasn't a perfect utopia, Nixon had largely delivered the stability he promised.
In 1972 he ran on "continue the good stuff" campaign, and people by and large bought it.
It no doubt helped him that McGovern was an unattractive
In the end it was a total blow-out. Nixon won 520 Electoral Votes.
Then the sniveling, conniving, virtue signalling Republicans sold Nixon down the river.