One of these days, some brilliant political operative working for one of today's dozen or so major-party presidential candidates will realize that apart from its new Feb. 5 date, California's primary election presents unique opportunities for anyone who wants to employ a little shoe leather.

For unlike what the name implies, the California primary is not really one big statewide election. The rules are slightly different on the Republican and Democratic sides, but the essence is the same: California is holding not one primary, but 53 small ones — one for each congressional district.

Take the Republican side first. Until this year, all GOP presidential primaries here have been statewide winner-take-all affairs. If someone got 34 percent of the vote, but was still the top vote-winner, he took all this state's delegates.

This time, the vote will be winner-take-all by congressional district. Each district will have three delegates up for grabs and whoever wins in that district will get all three. So 159 of the state's 173 overall GOP convention votes will be decided in individual districts, not statewide. Another 11 delegates will go to the statewide winner, with three top party officials getting automatic spots.

On the Democratic side, it is proportional representation by congressional district. Each district will have between three and seven national convention delegates to give. The state will also have 65 "super-delegates" — elected officials and party officers — among its total of 440 delegates.

All these arcane rules mean we should soon see major candidates hoofing it through areas normally hostile to their parties. For House Speaker Nancy Pelosi's solidly Democratic district in San Francisco still has a few Republican voters, and they will choose three GOP delegates.

Republicans now rarely go to San Francisco for anything but fancy fundraisers on Nob Hill or in ritzy neighborhoods like St. Francis Wood. But if a Mitt Romney or Rudy Giuliani wants those three delegates, he just might have to get off his airplane and hoof it around a Democratic district.

The same for Democrats. Better than 100 Democratic delegates will be elected from solid GOP bastions like Rep. Dana Rohrabacher's Orange County bailiwick and the Madera-area district of Rep. George Radanovich.

These areas have rarely seen a Democratic presidential candidate, but just as there are Republicans even in Pelosi's district, plenty of Democrats also live in Republican-majority areas. They represent a solid opportunity for a second-tier candidate like New Mexico Gov. Bill Richardson to move up in the delegate counts — if he's willing to venture there and meet those voters. To counter that, front-running Sen. Hillary Clinton of New York might have to make a few rather unusual stops.

So far, no candidate has done this. But whenever the rules change, so do the tactics. No sooner had California changed its primary date early this year than every major candidate revised his or her charter airplane schedule to begin campaigning here.

But so far, the assumption among candidates appears to be that this is one big state. That's wrong, and tacticians will soon realize it, if they haven't already. Yes, Democrats already had these rules in the last two primaries, but back then, the California primary was too late to matter so candidates John Kerry or Al Gore had no need to change their plans.

This also means Democratic candidates will have to air television ads in markets like Fresno and Redding and Bakersfield and San Diego, which they normally all but ignore during a primary. It means Republicans will have to advertise heavily in Los Angeles and the San Francisco Bay Area, with their plethora of safely Democratic congressional districts.

In fact, it's almost as if the two parties had suddenly carved up California into 53 small states, matching the number of congressional districts here.

If anything, this ought to make the early primary election season even more entertaining that it already promised to be. There's even the chance the new reality will allow many more Californians some personal contact with candidates they normally see only on television.

And that would be a truly refreshing change.

— Thomas D. Elias, of Santa Monica, is a columnist and author. His e-mail address is tdelias@aol.com.