I don't know why you keep expecting the Dems to act like a progressive political party. They aren't, and haven't been in our lifetimes. They are centrist at best, more likely centre right. They have a progressive wing in the party, but they are sidelined and hold no power whatsoever in the Dem establishment.
They've had one legitimate progressive make an impact since I can remember, and that only happened because the party elite cleared the entire field for the most hated corporatist Dem insider of the last 50 years to run unopposed. Which the entire party went along with), except for one guy who went rogue and who has never really been one of them to start with.
Even so, they aren't actively trying to destroy American democracy the way the GOP is openly doing.
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