The 1968 Presidential election took place after the assassination of Martin Luther King Jr. There were riots across the country, in response to the assassination and changes in the civil rights movement. Previous to that, Kennedy had been assassinated and there were demonstrations against the Vietnam war. The mood in the country was tense.
The Republican nomination was won by Richard Nixon, who promised to change the climate in the country to one in which peace was restored across the nation. The Democratic nominatation was won by Hubert Humphrey. The 1938 election was the last in which two previous vice presidents were running against each other. Both candidates had experience in helping to run the country and both were considered good candidates.
The 1968 presidential election followed the placement of Lyndon B. Johnson in office, after the assassination of President Kennedy. There continued to be race riots, civil rights movement riots and riots against the war. In contrast, there were also peaceful demonstrations around the nation.
The tension in the country regarding the Vietnam war, led to the decline in popularity for Johnson and he did not run again. In fact, he became so unpopular that he was not longer allowed to make certain public appearance, including those requested on college campuses.
The decline in popularity for Johnson, led to increased popularity for candidates against the Vietnam war. Candidates that were against the war were more popular and eventually Nixon won the election.