Why was the 1968 election a turning point in US political history?

A.
It saw the end of the New Deal coalition.
B.
It saw the first important third-party candidacy.
C.
It saw the Republican Party become dominated by eastern moderates.
D.
It saw the South swing to the Democratic Party.

Explanation:

The 1968 presidential election took place against civil unrest and tragedy, following the assassinations of Robert Kennedy and Martin Luther King Jr. Race riots and the ongoing Vietnam War had shaped public perception negatively against the incumbent Johnson administration.

Mismanagement of civilian affairs by generals at the front and by the government in the rear seriously exacerbated the economic and social upheavals associated with total war. The result was a year of revolution in 1917 that destroyed the monarchy, unchanged the empire, and led to a new communist state