Exactly this. You wanna push the Democratic Party leftward, you vote as left as you can in every election you can vote in, allllll the way down the ballot.
Not voting does not push in any direction at all.
Here’s my thread about one particular race in MA where the crucial election was, specifically, the local Dem party primary. Progressives failed by only ~1% in an election that usually has turnout of around 20%—and so we really could win this time if people turn out.
Yes, this.
And then, if you're ACTUALLY motivated, you call, write, harass and otherwise make your feelings known.
Elect and re-elect Democrats, however flawed and imperfect, then make them sorry they got the job because you don't give them a moment's peace!