Barry Goldwater made the argument that the Eisenhower administration and the Republican Party at large was largely just a Coke vs. Pepsi version of FDR’s New Deal. This is a good example of the “Both parties are the same” argument.
In Barry Goldwater, LBJ found the perfect opponent. Presidential journalist Teddy White observed that his “candor is the completely unrestrained candor of old men and little children.” The Arizona senator proposed authorizing NATO commanders to deploy atomic weapons. (“Let’s lob one into the men’s room of the Kremlin,” he offered on one occasion.) He suggested that the Tennessee Valley Authority—a landmark New Deal program that brought electricity to much of the rural and impoverished South—be privatized and Social Security made a voluntary program. He dismissed the Republican Eisenhower administration as a “dime-store New Deal,” and offered that “this country would be better off if we could just saw off the Eastern Seaboard and let it float out to sea.” Given his extreme temperament, it was unsurprising that his movement attracted the enthusiastic support of far-right fringe groups like the John Birch Society. “We’ve got superpatriots running through the woods like a collection of firebugs,” complained one of his state organizers, “and I keep running after them, like Smokey the Bear, putting out fires. We just don’t need any more enemies.” (Source)
In the 1950s and 60s, party idenity was not tied to lifestyle and morality in the way it is today. See The Wages of Political Data