Eh, I guess living in Texas has just led me to assume that other states do it that way as well.
What a waste of money though...
They assume that Presidential primary prestige in being early is better than cheapness.
Texas has some weird constitutional requirement (I think) that makes it quite hard to separate the two (or hold it much earlier than March 4), though the state leg. tried unsuccessfully to do so last year.
The primary used to be later, for example in
Terry v Adams (1953) the Jaybird primary was in May, and the Democratic Primary in June or July.
When John Connally was going to run for President in 1980 as a Republican, there was an effort to split the presidential primary from the state primary. This led to the Killer Bee episode in 1979 when 12 senators hid out to break quorum.
Flight of the "Killer Bees" In 1979, a March 11 presidential primary was proposed to give Connally the edge in an "early" primary, while the state primary would remain in May. As the presidential primary has been moved forward, it has dragged the state primary with it.
Perhaps the main reason that the proposal to move the presidential primary to February 5, 2008 failed, was that it was proposed to move the state primary with it. The filing deadline for state office ends in early January, roughly 60 days before the primary. Moving the primary meant moving the filing deadline back to 2007. County election officials were opposed because it would mess up with sending out new voter registration cards -- I think they would have had to do it in the week between Christmas and New Years when they were most likely to be understaffed. And there were also problems with the time periods with party affiliation. They couldn't get the 21 senators to move to 2nd reading in the Senate.
California used to have a June primary in gubernatorial election years, and a March primary in presidential election years. In 2007, when they moved to February 5, 2008; they split off the presidential primary, so that the statewide primary will always be in June.
