There is room for a lot of good faith debate here, but FWIW I reckon It is a mistake for the left to prematurely roll over and telegraph an inevitable Biden vote (whether on this or any other issue) just because Trump would be worse. The time for that utilitarian calculus is much closer to November. Right now, if you want policy change — you have to raise hell.
As much as you love to hate ‘em, this is what the Tea Party and their ideological successors got right about wielding power within their own party. When the time comes, by all means circle the wagons and vote pragmatically, but during primary season you have to come across as a credible threat to the party power structure.
I’ll personally be willing to (attempt!) to shame my progressive friends into voting blue, say, around October. In the meantime, I am proud of folks for speaking their mind and standing up for human rights.
I use mineral spirits, and have not had issues. Some folks recommend this stuff, But I have not tried it: https://www.tractorsupply.com/tsc/product/crown-psc-1000-parts-cleaner-5-gal