They are doing it because they think far-right Trumpist candidates will be easier to beat in the general elections than more moderate candidates.
What the Democrats are doing is sleazy in the best of circumstances. If you love your country more than your party, you should want the best candidates to advance in either party. And in these circumstances, what they are doing is insane: The far-right candidates whom Democrats are supporting could easily wind up winning.
Many Democrats, living in their own information bubble and apparently having learned nothing from 2016, do not seem to understand the horrific electoral landscape they are facing. They do not seem to understand how much their business-as-usual approach could lead to a full Republican takeover in 2025 — which as this week’s Jan. 6 insurrection hearing reminded us yet again, would be a disaster for our democracy.