If you chose not to vote for Biden, and that leaves Trump in power for four more years, enabling the most powerful country in the world to be lead by a proto-fascist who could have huge influence over the direction of politics in my country, you're being short-sighted and selfish
If I had to chose between the two I'd argue you should vote for Sanders. I said this before Super Tuesday and I stand by it. But since Sanders is no longer an option,actively sabotaging the centre-left in the name of ideological purity will just lead to same result as Corbyn here
2020 is a census year,there are Senate races to win, there are House seats to defend. If you really think that Biden, however hard he may be struggling to string sentences together, is worth losing that because you couldn't get 100% of what you wanted, your movement is fucked.
You will not win by crossing your arms and taking some imaginary high-road, not now and not in the long-term. You have enormous potential to make 2020 a foundation for better things, there are still people like AOC in Congress who need the triad to have any influence at all
And that's not even mentioning the Supreme Court, with potentially two justices on the liberal side close to retirement or even death. If you think Medicare for All will get through a 7-2 constitutionalist SC you are insane.
Build on Sanders successes, find new candidates for 2022 and 2024 and make the case that the Democratic party establishment can unite around your candidates because it is willing to work with them, however hard that may be to swallow. Sanders didn't do this and it screwed him