The Cold War and the Vietnam War had a lot to do with the politics of the 1970s. For example, it was the Vietnam War that helped Nixon win reelection in 1972. People felt that Nixon was the man to end the war and to help crack down on the disorder that the war had helped to cause in the US.
This disorder, added to the energy crises of the decade, helped to bring on the conservatism that would dominate the 1980s. People felt that the US had gotten too weak militarily and had been humbled by the OPEC countries. They wanted a stronger America and the conservatives promised them an America that would be stronger militarily and politically.