Why the Democrats had a bad 1968 Election year?

The 1968 United States presidential election was the 46th quadrennial presidential election, held on Tuesday, November 5, 1968. The Republican nominee, former vice president Richard Nixon, defeated the Democratic nominee, incumbent vice president Hubert Humphrey. Analysts have argued the election of 1968 was a major realigning election as it permanently disrupted the New Deal coalition that had dominated presidential politics since 1932.

Explanation:

Incumbent president Lyndon B. Johnson had been the early front-runner for the Democratic Party's nomination, but withdrew from the race after narrowly winning the New Hampshire primary. Eugene McCarthy, Robert F. Kennedy, and Humphrey emerged as the three major candidates in the Democratic primaries until Kennedy was assassinated. Humphrey won the nomination, sparking numerous anti-war protests. Nixon entered the Republican primaries as the front-runner, defeating Nelson Rockefeller, Ronald Reagan, and other candidates to win his party's nomination. Alabama governor George Wallace ran on the American Independent Party ticket, campaigning in favor of racial segregation.

The election year was tumultuous; it was marked by the assassination of Martin Luther King Jr. and subsequent riots across the nation, the assassination of Kennedy, and widespread opposition to the Vietnam War across university campuses. Nixon ran on a campaign that promised to restore law and order to the nation's cities and provide new leadership in the Vietnam War. A year later, he would popularize the term "silent majority" to describe those he viewed as being his target voters. He also pursued a "Southern strategy" designed to win conservative Southern white voters who had traditionally supported the Democrats. Humphrey promised to continue Johnson's war on poverty and to support the civil rights movement. Humphrey trailed significantly in polls taken in late August but narrowed Nixon's lead after Wallace's candidacy collapsed and Johnson suspended bombing in the Vietnam War.

Nixon won a plurality of the popular vote by a narrow margin, but won by a large margin in the Electoral College, carrying most states outside of the Northeast. Wallace won five states in the Deep South and ran well in some ethnic enclave industrial districts in the North; he is the most recent third party candidate to win a state.[2] It was the first presidential election after the passage of the Voting Rights Act of 1965, which had led to mass enfranchisement of racial minorities throughout the country, especially in the South.[3] Nixon's victory marked the start of a period of Republican dominance in presidential elections, as Republicans won four of the next five elections.