Why the landslide victory in 1964 for LBJ?

[Undesired Walrus]

Why did LBJ win so decisively up and down the country in 1964? For a man now known as one of the most unpopular Presidents of the last century, there seems to be a gap in the explanation behind his spectacular win that year?

[samm]

From what I have read on the subject the common theory is that sympathy for Kennedy carried over into not wanting to change horses from what he championed, combined with one of the classic implementations of mud slinging (nuclear bomb overlaid on little girl or something) against Goldwater.

[dudalb]

A.Vietnam had not happened yet and it was Vietnam that Made LBJ so unpopular.
B.Goldwater ran a campaign which, Goldwater himself later admitted, was very poor.