Fusionism was a term coined by Frank Myer back when National Review published serious writers. He meant something like a blend of libertarian and traditional conservative thought.
This was during the early years of the nascent post WWII conservative movement which was building a coalition opposed to the dominant liberalism that had ruled the country since FDR.
I don’t think Meyer fusionism fits either Levin or Shapiro.
A lot of what passes for conservatism today is just the mainstream bipartisan liberal consensus of the 1960s.
A lot of the silly talking heads calling themselves conservatives think that anything that isn’t leftism must therefore be conservative. And so by repetition people think that the Gene McCarthy, RFK liberal pablum of Dennis Prager is conservatism.
They sure aren’t as cultural as me u or Lew