Sam Smith
Politics is not religion. You're not proving how virtuous you are. You are finding the best Democrat who can beat Trump.
If you are a liberal you represent only 26% of the voting population. To win, you have to find someone who can attract support from the rest. Check who's doing the best in non-blue states.
National politicians are not activists, they're reactivists. You're not choosing the best candidate, but the best battlefield.
Liberals are considered elitists by much of the country. One way to deal with this is to concentrate on issues that affect the most number of voters, such as basic economic ones.