AIPAC may be able to spend close to $10m to ensure a 10-point margin in races with around 100k voters but... they're spending a lot of money per winning voter there. The initial results sting, but this is unsustainable for them? And a really bad look on top of everything else?

I think this is a problem with any special interest group that attempts to do this, by the way. I think the strategy doesn't really work in the long run. The candidates AIPAC backed were stooges who aren't good Democrats. They will not retain their seats when challenged next. It's a waste of $$$

It doesn't matter how much they spend when their grassroots progressive opponents run on small donations and volunteers. We can't win in a money war with them. And if they're able to help take out a bunch of progressives in one fell swoop, they'll scare enough people so they won't have to fight one.