Here is a fundamental problem with American politics: people don't trust Democrats. They don't trust Republicans either. They don't trust the media. They don't trust corporations. They don't trust any of our institutions.
Why? Because they keep getting fucked and nobody seems to care.
So you can say, "Not voting for Biden and letting Trump win will make everything worse." Because it's true! But it's not persuasive to people who things are just going to keep getting worse anyway.
