Every election year, political parties love to talk about all the hard work they've done registering new voters and how their candidates have energized certain blocs of voters.

It makes for nice rhetoric, and on the margins it probably does make a difference now and again. But here's the boring reality:

Most Californians register to vote not because a political cause has touched their heart, but rather because they checked a box on a form at the Department of Motor Vehicles when they received or renewed their driver's license.

Consider last year, a presidential election year in which voter participation was at its highest in decades. Over the course of 2008, records show that 171,094 voter registrations were turned in to county elections offices around the state. That may seem like an impressive number, but it is dwarfed by the 310,310 registrations that came in through the DMV.

Now, think about what age most people receive their first driver's license. It's either 16 or 17, which is too young to vote. There are many reasons why potential voters from 18 to 24 are the least likely to be registered of any age group, but right up there has got to be the fact that at the time it is most convenient for them to register, they are slightly too young to take advantage of it.

A half-dozen other states have taken a look at similar numbers and decided upon a relatively elementary solution: Let teenagers pre-register to vote so that when they do turn 18, they are placed on the voter roll. It's not a partisan idea. Red states (Florida and Louisiana) do it and blue states (Hawaii and Oregon) do it.

California will do it, too, if Gov. Arnold Schwarzenegger decides in the next couple of weeks to put his signature on AB 30. The bill would allow all 17-year-olds to preregister so that they are able to vote in the first election that comes around after their 18th birthday. Many 17-year-olds already have that right; they can pre-register if they are going to be 18 at the time of the next election.

Alas, as with nearly every other issue under the sun, the California Legislature decided that this was a partisan issue: Every Democratic lawmaker voted for it, and every Republican lawmaker voted against.

To be sure, the Republican opposition represents a certain fear factor. Exit polls from last year's presidential election show that President Barack Obama carried the 30-and-under vote by an overwhelming 34 percentage points.

Had the same bill come up in the 1980s, however, partisan considerations would have been reversed: Exit polls from the 1984 and 1988 presidential elections showed that Ronald Reagan carried young voters by 20 percentage points and George H.W. Bush by 26 points. In 1980, in fact, some polls showed that young voters were more solidly pro-Reagan than any other age group. Partisan concerns are temporal. Sensible public policy should not be.

"As you look at other states, this has been a thoroughly nonpartisan or bipartisan issue," said Blair Bobier, deputy director of the New America Foundation Political Reform Program, which sponsored AB 30. He notes that Florida Gov. Charlie Crist, a Republican, has been a strong supporter of preregistration.

Bobier said enactment of AB 30 would promote goals that ought to be objectives of every government operation: uniformity and simplicity.

Under current law, some 17-year-olds can register, some can't. It depends on when their birthday falls and when the next election is scheduled. "It does create some confusion," he said. "We're trying to make this as simple as possible."

The bill does not mandate or even suggest that high schools actively promote voter registration, but it does seem a natural. Every California senior - most of whom start the year at age 17 - has to take American government as a graduation requirement.

"For a lot of kids, high school is the last institutional engagement they have before they go off on their own," Bobier said. "Voter registration ought to be part of that engagement. We are hopeful that there will be a volunteer groundswell to bring voter-registration activities into high school."

In an effort to persuade Schwarzenegger to sign the bill, the New America Foundation will host a Capitol news conference on Thursday at which members of an association of high school student councils will appeal for the governor's support.

Standing at their side, Bobier said, will be a representative of the AARP. "This issue cuts across generational lines," he said. "Everyone sees how much sense this makes."

- Timm Herdt is chief of The Star state bureau. His political blog "95 percent accurate*" is at http://www.TimmHerdt.com.