Imagine you were a wizard and could force everyone on Lemmy to vote for a single third-party candidate. Also assume every account on every instance of Lemmy is a US citizen capable of voting. Lemmy has about 421 thousand users. Even if each account on Lemmy could magically convince 50 other eligible voters to vote for the same independent candidate, that would only amount to about 21 million votes, or about 16.3% of all votes in the election going towards that candidate.
Voting in an independent party is nothing short of impossible in the US.