The BEST way to elect progressives is to invest in the grassroots organizing groups that are on the ground 24/7/365 doing the work to go beyond platitudes and instead are achieving public policy wins for normally marginalized people at the local, state and national levels.
They also help these people organize themselves so that they can advocate for their own priorities — a novel concept— which leads to them BEING and, importantly, FEELING empowered. This leads to increased trust in institutions and the political system, which in turn grows participation and voter turnout.