California has done it again: rescheduled its presidential primary so that it will vote earlier in the presidential selection process. Instead of voting in early June, at the end (or just about the end: Utah voted later last time) of the primary and caucus system, California will now vote in March. Of course that may not be early enough to make California the central focus of presidential politics. In the 2008 cycle it voted in February, and even then 33 states voted earlier or on the same day.

Which is not to say that California has not made a difference in selecting presidential nominees. Voting in June, it provided narrow but decisive victories for Barry Goldwater over Nelson Rockefeller in the 1964 Republican primary and for George McGovern over Hubert Humphrey in the 1972 Democratic primary. From those results, and from Ronald Reagan’s success in the 1966 Republican gubernatorial primary and the 1966 and 1970 general elections for governor, some (including me, at the time) drew the conclusion that California was partial to the (arguably) extreme candidates of both parties, and would tend to tilt their nominations in that direction.

There was a certain tension between that idea — that California was somehow at the leading edge of both conservative and liberal politics — and that it was a reasonable bellwether of national opinion. In support of the latter view, however, you could cite data that showed California voting very much like the nation as a whole in presidential general elections, generally not varying as much as 5 percent off the national Democratic and Republican percentages (more in 1968, when George Wallace took 14 percent of the national vote but won only 7 percent in California).