I'd like to know why there seems to be a need for daily jabs at "the left" on what is supposed to be a Democratic message board.

The Democratic party claims to be a "big tent" party, and is supposed to be the liberal political party in the US, isn't it?

....on what is supposed to be a Democratic message board?

I hope the reason for that would be spelled out in my post. If not, ask and I'll explain myself. I can't explain for others.

But there are also quite a few progressive nominees in swing districts who look like they have a shot. Their overall strength will be based largely on our success in those places.

It seems to indicate that often Democratic Voters would actually prefer more progressive representation if that is possible. Safe Blue seats are a good place to start. As it becomes more normalized for Congressional representatives to stake out positions further left of center, the overall policy spectrum of what is considered mainstream enough to win general elections starts to shift left as well. That is what has happened with Medicare for All. I think of these races as a leading indicator.