I wrote this commentary in response to an article by Professor Jeffrey Sadow of Louisiana State University at Shreveport.
I have followed since 2001 the controversy surrounding Washington state's election system.
In 1996, California enacted its partisan blanket primary by popular initiative and first used it in 1998. This put all candidates of all parties on the same primary ballot, and the top vote-getter from each party advanced to the general election. In 2000, the U. S. Supreme Court (SCOTUS) reversed the two lower courts and struck down California's blanket primary.
Washington state had used the partisan blanket primary since 1936 and attempted to keep it. In 2004, however, the federal courts also declared it unconstitutional. In November 2004, Washington voters passed an initiative for a Louisiana-style "top two" system. (All candidates, including independents, run in the same election. The top two vote-getters, regardless of party, advance to the runoff.)
Washington's "top two," because of federal litigation, has not been implemented. The state has instead used open primaries. (The parties have separate primary ballots, and each voter picks a party on primary day.)
In his majority opinion in the 2000 California case, Justice Antonin Scalia called the "top two" a "nonpartisan blanket primary." He said that it is constitutional because "voters are not choosing a party's nominee." (In his dissent, Justice John Paul Stevens-- correctly, in my view-- stated that the "top two" is a general election with a runoff.)
The Louisiana/"top two" is a nonpartisan system because the parties have no way of officially nominating candidates, and the general election (the first round) is not limited to one candidate per party. (Each party, of course, may endorse a candidate.)
In my view, when party labels are put on a Louisiana/"top two" ballot, it's mainly for the voters' information. If a candidate has a party preference, he has that preference whether the party likes it or not. Thus, I was surprised on October 1 when the justices showed sympathy for the parties' argument against allowing party labels on the "top two" ballot. If SCOTUS indeed strikes down the "top two" for that reason, there will, if necessary, be a new Washington initiative for a "top two" without party labels. And the voters will again pass it overwhelmingly.
Louisiana, unlike Washington, registers voters by party, and it will be interesting to see how this ruling affects the Bayou State.
All of this (and more) is covered in greater detail here