In modern era, most democracies that morph into autocracies do so through voting. Voting for an autocrat in a Democrat system doesn’t mean you support democracy, it means you support an autocrat through the means available, which is voting.
“But there is another way to break a democracy. It is less dramatic but equally destructive. Democracies may die at the hands not of generals but of elected leaders—presidents or prime ministers who subvert the very process that brought them to power. Some of these leaders dismantle democracy quickly, as Hitler did in the wake of the 1933 Reichstag fire in Germany. More often, though, democracies erode slowly, in steps.”
What Tom Nichols is implying here is that the 51% of Americans who voted for Trump don’t care about American democracy, which is an odd thing to say considering that casting a ballot for your preferred candidate is the biggest democratic act a citizen can engage in. But ok.