PRACTICALLY EVERY poll conducted in the course of Virginia's gubernatorial race suggests that voters put education at or near the top of their list of priorities, a fact worth noting as the candidates brawl over the death penalty, abortion, immigration and other wedge issues that have come to dominate the campaign. In fact, Lt. Gov. Timothy M. Kaine, the Democrat, and former attorney general Jerry W. Kilgore, the Republican, have some intriguing things to say about education. What sets the two apart is the question of credibility: Mr. Kaine, whom we have endorsed, has some. Mr. Kilgore doesn't.

Mr. Kilgore has placed particular emphasis on finding, keeping and paying teachers. His proposals, some of which are already in use in school districts in Northern Virginia and elsewhere, include paying off new teachers' student loans if they spend five years working in tough schools; boosting teacher pensions; and providing state funding and tax incentives to teachers who pursue advanced degrees and additional training. Mr. Kilgore, whose wife, Marty, is a former public schoolteacher, would also establish a bonus system for teachers who secure advanced degrees in shortage areas such as math or science, and he would expand a bonus system for teachers who complete the National Board Certification process and elect to work at disadvantaged schools. These ideas have merit.

In addition, he has proposed setting up a performance-based pay regime that would break the entrenched system by which outstanding teachers earn no more than substandard ones. In theory, it's a fine idea; who would oppose incentives of all sorts to retain and reward the best teachers? In practice it's both devilishly difficult to fashion a workable, equitable system and probably dauntingly expensive as well. And it is on that second point -- cost -- that the Republican's approach to education begins to crumble.

The essential point to remember regarding Mr. Kilgore's record on education is that he opposed Gov. Mark R. Warner's sweeping tax overhaul and increase last year, an initiative that yielded $1.5 billion over two years, mostly for public schools. By working against the Warner tax plan, Mr. Kilgore undercut his future credibility on education generally; by posing now as the anti-tax candidate, Mr. Kilgore makes a mockery of his own education program. After all, none of his ideas on teacher pay is remotely plausible without the Warner tax formula plus, in all likelihood, another healthy infusion of fresh tax revenue on top of it. He speaks, for instance, of creating an "education investment trust" that would channel so-called surplus funds for school construction and give parents a $500-per-child education tax credit for the purchase of computers, software, tutoring and other non-tuition expenses. But Mr. Kilgore would use the very same "surplus" revenue to pay for the tens of billions of dollars worth of new roads the state needs. Without a willingness to invest in the state's future, where on earth would he find all this "surplus" money?

Mr. Kaine's ideas on education are somewhat more modest. But unlike his opponent, he backed the Warner tax package. That alone makes Mr. Kaine's views worth taking more seriously, even if he is not exactly forthcoming about what future sources of revenue he would tap or what competing priorities he would cut.

The centerpiece of Mr. Kaine's plan is a plan to make high-quality, free preschool universally available for 4-year-olds. Fewer than half of the state's 4-year-olds are enrolled in preschool now; Mr. Kaine figures 80 percent would sign up for a good, free program preceding kindergarten. He says the plan would cost $300 million, phased in over four years -- and that doesn't include the price of any new construction that might be required in school districts that are crowded, such as Loudoun County's. He has also said Virginia should fully fund the standards it requires of local school districts, a proposition that could cost as much as $1.2 billion in the state's next two-year budget. Those are pie-in-the-sky ideas unless he devises a way to pay for them. But Mr. Kaine, unlike his opponent, has a track record of making tough decisions to channel money to education. For that he deserves the benefit of the doubt.