I can give you the background on the change CA made. Imagine a district with the following breakdown: 35% Progressive D, 35% Liberal/moderate D, 25% Republican

I can give you the background on the change CA made. Imagine a district with the following breakdown: 35% Progressive D, 35% Liberal/moderate D, 25% Republican, 5% Other. So overall, 70% D. CA used to mandate that on the final ballot, you got one choice per party, e.g. one D, one R, and N "Other". Here's what would happen: the D primary would have a Progressive and a Liberal/moderate. But because Progressives were a lot more "activist", they got out and voted in the primary and their candidate would win. So the final ballot would be: Progressive D, moderate R, N "Other". In the election, enough Liberal/moderate Ds would NOT vote for the Progressive D, so the moderate Republican kept winning, despite only being 25% of the electorate and not voting with Democrats in the legislature, even though 70% of their district were Democrats. The change was to have the top two candidates of any party on the ballot. This resulted in a Progressive D and a Liberal/moderate D (and no R). R's (of course) vote for the Liberal/moderate D in this scenario on the final ballot, and they win (and vote with the Democrats in the legislature). This, more or less, is why Democrats have a supermajority in CA, but it's really two wings of the same party, and they have to negotiate much the same way that Democrats and Republicans in the US Senate have to get along.