The way forward for democrats is a universalist class politics.
Message needs to be that if you work hard and play by the rules, no matter who you are, you can have a decent life. Healthcare costs too much, rent is too high, homes are unaffordable, and we're going to do everything we can to make those things attainable by ordinary people. And while we'll be compassionate in reasonable ways on immigration, we're going to prioritize helping people here who need it, right now.
Democrats won on abortion, they won on gay rights, they won the culture war. It's done. Trump will be out office and they'll, thankfully, have no reason to run against a person rather than on issues. They need a vision for ordinary people.
Basically, they need a Bernie Sanders type who is younger, more affable, and doesn't call himself a socialist.
Whoever that person is.