1972

I know from personal experience. 17 year old me was one of them.

RESIST!

Ok. I see.

Sure, he was with anti-war protesters like me, but as you have already alluded to, we did not represent the priorities of the general public. Nixon won the middle by governing mostly in a moderate manner and moving to preempt issues that could have benefited Democrats. Nixon "opened up" China during the 1972 presidential campaign, and he signed two historic nuclear arms treaties with the Soviet Union during the same time period. The carpet bombing of Cambodia and Kent State and all that followed was in the Spring of 1970 and perhaps marked the peak of public opposition to the Vietnam War, and that helped Democrats in the Fall 1970 elections. But Nixon was also pursuing a policy of "Vietnamization" which was reducing the American footprint in Vietnam. This from Wiki:

"On August 12, the last American ground combat division left the country. However, the U.S. continued to operate the base At Long Binh. Combat patrols continued there until November 11 when the U.S. handed over the base to the South Vietnamese. After this, only 24,000 American troops remained in Vietnam and President Nixon announced that they would stay there until all U.S. POW's were freed." So by the time the 1972 elections came around the war was no longer as much of a hot button issue as it was in the 1970 Congressional elections.

Meanwhile, on the domestic front, Nixon established both the Occupational and Safety and Health Administration (OSHA) AND the Environmental Protection Agency (EPA) during his first term in office. Nixon was a VERY different type of political player than is Donald Trump, who revels in giving the middle finger to everyone who is not a part of his hard core base. It saddens me to say so, but Nixon, while polarizing to people like me, was far from being "a very unpopular President" He was an overwhelming favorite to defeat any Democratic candidate in 1972

Just for perspective Reagan had a 58% percent approval rating 1984. Unfortunately Nixon was indeed a very popular president going into that election.