Several California newspapers have recently endorsed Proposition 14, and they all say the same thing in their editorials. They all assert that California’s legislature is polarized and that a “top-two” system will make the legislature less polarized and less partisan.

However, the political scientists who have studied polarization in state legislatures do not agree. Assistant Professor Boris Shor of the University of Chicago prepared a graph early this year that shows the degree of partisan polarization in each state’s legislature. His chart, listing all the states in order of conservative-to-liberal (as measured by state legislative votes plus their answers to questionaires), can be seen here.

California’s position on the bottom of the chart is meant to show that California has the most liberal legislature in the nation.

States are not listed in order of polarization.

The chart does show that California’s legislature is the most polarized, but it also shows that Washington state’s legislature is almost as polarized as California’s legislature. Washington state used a blanket primary 1934 through 2002, a classic open primary in 2004 and 2006, and a top-two primary in 2008. If it is true that blanket primaries and top-two primaries counteract polarization, Washington cannot be explained. Washington state has, on the average, that third-most liberal Democratic legislators in the nation. Only the California Democrats, and the New York Democrats, are more liberal. Washington state Republicans in the legislature are considerably more conservative than Republicans on the average in the nation.

Political scientist Eric McGhee, of the Public Policy Institute of California, has been speaking at various places in California about Proposition 14, and his presentation includes the Shor chart. McGhee’s op-ed in the San Francisco Chronicle last month also agrees that California’s polarization is not a function of its primary system.

Political scientist Seth Masket also commented on the Shor chart on his blog. He says, about Proposition 14, “Given that other evidence about primaries and partisanship suggests little relationship between the two, I doubt the initiative would have anything close to the impact its backers suggest.” Masket is the author of the book, “No Middle Ground: How Informal Party Organizations Control Nominations and Polarize Legislatures.”

The May 2 Washington Post has this interesting collection of short essays, by six authors, of whether the U.S. would be better off with a third major party. Part of the impetus for this question is the May 6 British election, and part of it is the decision of Governor Charlie Crist to run as an independent for U.S. Senate in Florida.

The commentary by Newt Gingrich is not accurate when it says that the United States has experienced only one switch in the identity of the two major parties since 1828. Gingrich properly acknowledges the mid-1850’s, when the Whig Party mostly died out and the Republican Party became the newest major party. But he ignores the period 1834-1836, when the National Republican Party died and was replaced by the Whig Party. The National Republican Party existed from 1825 through 1835. It ran John Quincy Adams for re-election in 1828, and Henry Clay in 1832. Thanks to Rob Richie for the link.

The Guardian, one of the leading daily newspapers of Great Britain, has this lengthy editorial, which resoundingly endorses proportional representation, and also endorses voting for the Liberal Democratic Party in the May 6 election. Thanks to Gene Berkman for the link.