If so, it is the first time the Democrats stole an election for President, while splitting their ticket and giving the Republicans a solid win in almost everything else. The Republicans won 2/3 of Senate races, split the House almost even denying the Democrats a workable majority, the state elections went well for Democrats, and referenda went poorly for the “progressives” (as socialists prefer to be called).
Arguing that cheating Democrats elected Biden, while supporting Republicans for everything else is not a viable theory. Tammany and Boss Daley and the like, never split tickets.
A better explanation, is that Trump was unpopular with many Republicans. Remember that Republicans in modern times have been hawks on foreign policy, in favor of small government and against deficits, tax and tariffs, and in favor of immigration. The Reagan Republicans turned out to support the party and win referenda, but enough were mad at Trump to affect the outcome.