Do a hostile takeover of the GOP instead. Many states don't care why party you register as, and if they do just register as a Republican and vote in their primaries. Pick a socialist candidate and get them to run as a Republican, and vote for them. This is in essence what Trump did, but of course he did it for fascism and got Nazis to vote Republican. The same strategy can work for anyone else. This can start in safe blue states where no one votes in the GOP primaries and spread from there.
This is a far more realistic strategy because third parties are vulnerable to the spoiler effect and will always fail due to people being worried about electing Republicans.
That's what they did this election, and we got fascism and the DNC doesn't matter anymore. So now what?