Yep a crazed socialist who loved swinging. Not my idea of a major thought leader.
https://en.m.wikipedia.org/wiki/Robert_A._Heinlein
Heinlein ceased considering himself a Democrat in 1954. He was among those who in 1968 signed a pro-Vietnam War ad in Galaxy Science Fiction.
Heinlein considered himself a libertarian; in a letter to Judith Merril in 1967 (never sent) he said, “As for libertarian, I’ve been one all my life, a radical one. You might use the term “philosophical anarchist” or “autarchist” about me, but “libertarian” is easier to define and fits well enough.”