It's difficult to open a car door in Hawai'i these days without hitting a potential candidate for the U.S. House.

The decision by Rep. Ed Case to make a run for the Senate has opened a rare void that is being filled, or soon will be filled, with an avalanche of wannabe U.S. representatives.

Most of the action so far is on the Democratic side, where three people already have filed and many others are considering or intending to make the run.

This guarantees that the nominee on the Democratic side, at least, will be a plurality winner, going into the general election with support from far less than half of his or her primary voters.

On the Republican side, there has been less action, although former candidate Mike Gabbard clearly is interested. And there are signs that the forces of Gov. Linda Lingle may put muscle behind someone like Micah Kane, the personable chairman of the state Department of Hawaiian Home Lands.

The GOP strategy is obvious: Let legions of ambitious Democrats fight it out in the primary while Republicans save their ammo and energy for the one-on-one race in the general.

It could add up to a rare opportunity for the Republicans to pick up a seat they have not held in years.

In a crowded Democratic primary where plurality is all that matters, conventional wisdom says the advantage goes to established candidates with solid institutional support, particularly from unions. One doesn't need broad appeal as much as one needs a solid core backing.

That generally works against so-called "maverick" candidates.

This theory was challenged in late 2002 and early 2003 when Case prevailed in back-to-back elections to take the late Rep. Patsy Mink's seat.

But these were one-shot, winner-take-all elections where the power of institutional backing doesn't have the same oomph as in a traditional Democratic primary.

In addition, Case had huge statewide name recognition from a recently completed campaign for governor.

Those two elections drew about 40 candidates each time. While the numbers this time around may be slightly smaller, it will still be a full and varied field.

One of the unfortunate prospects is that this race, which is attractive to politicians on many levels, will draw in candidates already serving and contributing at other levels.

In some cases, such as with state Sens. Ron Menor and Gary Hooser and likely candidate Colleen Hanabusa, they will not have to give up their current jobs to run. But others, such as state Rep. Brian Schatz (already filed) and state Rep. Roy Takumi or Kirk Caldwell (considering it) would have to give up their positions of influence to make the race.

At one level, you want to see public officials with talent and ambition go for the brass ring. But only one can win; the others will be lost — at least temporarily — to public service.

Reach Jerry Burris at jburris@honoluluadvertiser.com.