The Democratic Party is a long-standing "bankers party" and "corporatists party" (a party for big companies and organizations). In that sense, they're just as "bad" as the Republican Party, and due to how the whole democratic system is set up in the USA, Americans are in reality bereft of alternatives. Picking anyone else than those two, is effectively a blank vote. This system can at least in part explain why so many Americans choose to stay at home during the elections, because to them, for whatever reason, it doesn't really make much of a difference who is in power.

This is why it's important to vote in primaries and to cultivate leaders at the local level. The Republicans became a lock-step far right party by building up infrastructure and candidates at the lowest levels and building from there. Too many progressives don't seem to pay attention to any elections below the presidential election (and then whine that things are rigged when their candidate gets less votes than someone they don't like).

The Republicans deliberately built the grassroots top down, with targeted media and subsidised networking. Supposedly grassroots orgs were aggressively seeded and astroturfed.

It's not that progressives don't pay attention, it's that the Democratic machine doesn't do this. In fact it works to sabotage and disempower effective grassroots opposition to its corporatist policies.

There are always a few break outs in every cycle - like Cori Bush this year - but they're there for show, not for policy. If they get too pushy they run into opposition, and if they don't accept a compromise with the party line they're quietly removed by PACs that funnel non-grassroots special-interest money to challengers.

To be fair, the presidential election thing progressives are whining is rigged is that their candidate lost despite getting 3 million more votes than someone they didn't like.

That it happened twice in 3 presidents is icing on the "it's rigged" cake.

I was referring to whiners in the primaries. There are many factors for why trunmp won in 2016 and changing any one of them could have changed the outcome. One of those factors was Sanders voters who stayed home or voted for third-party candidates.

They are not, alone, responsible for it, but it is still a fundamental difference in the parties; some Democrats are pro-big-business, but only one party has public-private partnership as a party plank.

Democrats may profess to be anti-big-business, but in practice they clearly aren't.