They could start by getting more candidates in the Senate, by more aggressively advocating for policies that will genuinely help people. It really seemed like Bernie Sanders's policy proposals resonated with a majority of Americans, but the Democratic Party did everything they could to sink him. Their more moderate proposals were less exciting, which I think is why the election between Biden and Trump was so close. If the Democratic Party had gotten behind more popular policies, they could have won more seats in the Senate too.
The problem, of course, is that both parties (though not Bernie Sanders) are beholden to big corporate interests. So they have to fight for lukewarm policy that doesn't really excite the people, but satisfies their major donors. They could fix this by advocating for election reform, but I don't think the party establishment really wants to change that.
It is worth noting that Bernie Sanders even did a town hall style meeting on FOX news, with positive reception. The Democratic Party could see the value in what Bernie was doing and support candidates like him, but they choose to go after big corporate interests instead. And I think that is their folly.
It does not make any sense to me that voters are voting for the exact opposite of Bernie (Republicans) rather than voting for someone closer to Bernie (Democrats).
> but they choose to go after big corporate interests instead.
Yet we established in this very comment chain that Democrats have passed some significant bills against big corporate interests, and Republicans have done the opposite.
> It does not make any sense to me that voters are voting for the exact opposite of Bernie (Republicans) rather than voting for someone closer to Bernie (Democrats).
> Yet we established in this very comment chain that Democrats have passed some significant bills against big corporate interests
I don't believe we established that? I allowed that these two bills you mentioned may have benefited labor, but that is not the same as going against big corporate interest. Certainly some labor policy would go against corporate interests (and that policy I believe is unsuccessful), but the ACA has been described as a massive government handout to insurance companies.