This argument doesn't really work in your favor, Leftist organizing was much stronger under Trump, because liberals had a common enemy with Leftists.
That said, we have got to get out of this constant cycle of only having two options. There’s too much money at a national level to start there. We’ve got to start local and get third party candidates into offices at a city level, then state, then national. It’s going to take a long time and it should have happened so very long ago. We can’t change the past, we can only change the future. The only time to start changing the future is in the present.
This has no chance of working. Electoralism is designed to not work like that. If any third party showed any chance of winning at the local level, the DNC and GOP would collaborate against them. We have seen this in Georgia, where they kicked PSL off the ballot. The only way to legitimately get somebody not in the DNC or GOP in power is via Revolution.