Make me do it, but quietly, preferably by communicating your desires through the medium of sternly worded opinion pieces in elite publications written by conservative-curious graduates of elite schools. When David Brooks and Jon Chait are displeased, that's when it will be time to listen. That really was the message sent during the Obama era. But activism, when it happened, worked. Occupy Wall Street, Black Lives Matter, Fight for 15, ... I don't mean these worked in the sense of achieving victory and going home. It never works like that. But they brought attention to issues, made people nervous, and changed the course of politics. Wall Street wasn't reined in and police killings of unarmed black people have not stopped, but there is more attention to these issues. Democrats will find it difficult to win while being too close to Wall Street, being "tough on crime," and without supporting (or at least pretending to support) a much higher minimum wage.
The time to protest is when Democrats are in power. Sure they'll tell you that the liberal utopia was ruined by all those nasty hippies in the 60s, and we'd better not repeat that, but that's not really what happened. Protesting now can, at best, stop horrible things from happening. Protesting when Dems are in power can potentially cause good things to happen.
It's just one part, of course. Some sternly worded opinion pieces probably help, too. Gotta make noise to be heard, and despite denials, politicians keep proving that it works.