after the 1964 election, president johnson believed that\n○ his stance on the civil rights act had been a…

Brief Explanations:

After the 1964 election, President Johnson won a landslide victory. This victory gave him the confidence that he had public support. His social programs, like the "Great Society" initiatives, were in line with what he thought the public wanted. He did not believe his stance on the Civil Rights Act (which he supported) was a mistake. He also won the election, so the idea that he "would never be able to win political office again" is wrong. And there's no indication from the election result that the public no longer cared about Kennedy's legacy (Johnson was continuing some of Kennedy's initiatives in a way, like the push for civil rights which Kennedy started).

Answer:

he had public support to continue his social programs.