1969-1977 : President Robert Henry Winborne Welch Jr. (R-MA)

[Huey Long is a Republican]

In 1950, Ultraconservative businessman and future founder of the John Birch Society ran for Lieutenant Governor of Massachusetts, losing to State Treasurer Laurence Curtis by 29.74 % in the Republican Primary. Say that MacArthur and Taft endorses him and campaigns for him a bit, allowing him to barely win the primary and then the general. He then stays as Lieutenant Governor until 1958 where he runs and defeats Governor Foster Furcolo in a close race due to being an established incumbent LG of four terms. As Governor, Welch continues his extreme conservatism and continues to head the JBS and appoints an ally of his to replace JFK in the Senate when he becomes President. In 1967, he leaves the office to his LG John A. Volpe and runs for President, becoming the Nominee in 1968 for the GOP though Liberals for the most part walkout and Buckley declaring that the Conservative movement should let Welch lose. Welch wins, largely due to Wallace backing his campaign, his WWC messaging, and him getting a lot of anti-war votes from the youth due to him being against Nam (being an advocate of fortress america essentially means he's going to be against Nam escalation no matter what) well being the head of the JBS and his extreme anti-communism keeps the Conservatives in line to vote for him. He wins a squeaker in 1968 and goes on to serve two Presidential terms, winning re-election in 1972.

Who is his running mate (I personally think he'd reach across the aisle to get a Southerner, either Thurmond, Eastland, or Long though I can see a Moderate Republican being forced on him), who is in his cabinet, who is his judicial picks, what is his relationship with Director Hoover, and what does his administration look like in terms of policy?

[Blow by blow, the passion dies]

He would be unable to return to classical liberalism on economics due to the post-war consensus, and his states' rights agenda wouldn't go through Congress either.