What is a key reason goldwater lost to johnson in 1964?

The United States presidential election of 1964 was the forty-fifth presidential election of the country. It was held on November 3, 1964. President Lyndon B. Johnson had come to office less than a year before because of the assassination of his predecessor, John F. Kennedy. Johnson, who successfully associated with Kennedy's popularity, won 61.1% of the popular votes, the largest gain by a candidate since 1820. This was the sixth most unequal presidential election in US history. No Democratic candidate in the post-1964 elections achieved better results from the Electoral College than Johnson in 1964.  

Republican candidate Senator Barry Goldwater of Arizona suffered from a lack of support from his own party and his extreme right in political positions wasn't attractive to moderate voters. Johnson's campaign successfully portrayed Goldwater as a dangerous extremist, and defended social programs that became known as the Great Society. Johnson easily won the presidency, securing 44 of the 50 states and the District of Columbia.

the correct answer is b

hope i someone

what are the answers