Objectively, Buckley was not a pro lynching racist. Using his own reasoning, I would say QAnon followers are not civilized.
Buckley himself had developed two arguments against civil rights, both of which were little more than disguised racism, both of which led the line at National Review. The first emerged early in his career. Since the 1950s, Buckley had argued that civil rights should be opposed not because black people were biologically inferior to white people, but because they were not yet “civilized” enough to take part in democratic government. Or, as Buckley put it in 1959, “There are no scientific grounds for assuming congenital Negro disabilities. The problem is not biological, but cultural and educational.” He managed to change his mind somewhat over time, to his credit.

Who is using invectives is in the mind of the beholder. Facts and truth are required in a democracy.

It took many intermediaries to go from Buckley to Trump. I could list several but choosing a starting point is only arbitrary.