I managed to calculate some ideal points for the current California Assembly, based on the roll call votes from 2009. (Jeff Lewis provided the raw data on that, and I used W-NOMINATE to calculate the scores.) Here's a histogram, divided up by members' votes on the Maldonado confirmation:
Wesley Hussey calls a "coalition of extremes," where the far left and far right vote together against the middle. But as you can see, there's basically no middle in the California Assembly. Just that one person around the zero point (Democrat Alyson Huber of Lodi).
That said, there's still a bit of a pattern. As you move further to the left among the Democrats, the chances of a member voting no increase. However, you can find more ayes among the slightly more moderate Democrats. So it's reasonable to say that Maldonado was backed by all the Republicans and some of the more moderate Democrats.
By my count, Maldonado still needs four Democratic votes in the Assembly. If he starts with the most moderate and proceeds toward the extreme, that would meaning switching the following legislators (listed here with their W-NOMINATE scores):
- Alyson Huber (-.083)
- Manuel Pérez (-.591)
- Cathleen Galgiani (-.595)
- Juan Arambula (-.632).
Arambula has recently shifted his party affiliation from Democratic to Independent, so it's possible he's more moderate today than his ideal point above would suggest. Still, it's a notable how quick the jump is from the moderates to the extremes. Switching these votes won't be easy.
Oh, and if you want to see what polarization looks like, here's a scatterplot of the first two dimensions of roll call scores in the 2009 California Assembly: