LT. GOV. TIMOTHY M. Kaine's triumph in Virginia's gubernatorial race is a watershed -- the victory of a Southern Democrat who prevailed despite his principled opposition to the death penalty and his refusal to rule out new taxes.

Certainly his campaign was helped by the Bush administration's stumbles and setbacks this fall and the Republicans' resulting malaise. It was also Mr. Kaine's good fortune that the popularity of his principal Democratic ally, Gov. Mark R. Warner, peaked just as Republican fortunes dipped. But Mr. Kaine, by running a relatively positive campaign, also managed to convey his integrity, decency and intelligence -- as well as his faith as an observant Catholic -- while fending off fierce, and at times cynical, attacks by his chief opponent, former attorney general Jerry W. Kilgore.

As a candidate, Mr. Kaine's signal failing was to finesse the most serious challenge facing the state over the next four years: transportation. As governor, he is likely to confront an early test on the issue. It's been nearly 20 years since a Virginia governor took serious steps to address the state's stressed road and rail network, and the pressing need for fresh revenue may well define Mr. Kaine's term in office. If he hews to his campaign platform, in which he insisted that transportation funds be "locked up" by a constitutional amendment whose passage would take most of his four-year term, then he will have deferred, not dealt with, a mounting crisis.

If Mr. Kaine genuinely seeks a long-term strategy to keep traffic flowing on the state's roads, he will need to move beyond the campaign's go-slow rhetoric and seize the moment -- probably in the General Assembly session that begins in January, just as he will take office. He will need to make his case persuasively to the public and to court moderate Republicans who hold the swing votes in the House of Delegates.

In that he has a playbook to guide him: Mr. Warner's successful tax overhaul and increase nearly two years ago. While Virginians tilt Republican and say they dislike taxes -- who doesn't? -- Mr. Warner's 2004 package spread the pain equitably and won broad popular support, to the dismay of the right wing. In that fight, sensible Republicans in Richmond showed that they were more concerned with investing in the state's long-term health than in waving partisan banners. Mr. Kaine, an astute observer, will need to adapt the lessons he learned from Mr. Warner and apply them wisely.

Some Democrats in Virginia may crow that Mr. Kaine's victory, following Mr. Warner's successful four years in office, portends a leftward shift in the state's political orientation. Some Republicans may insist that in the absence of an overriding state issue, it was mainly a referendum on the battered presidency of George W. Bush and that the president's travails doomed Mr. Kilgore's candidacy. The sounder conclusion is that Mr. Kaine's triumph proves that a strong, smart candidate can win in Virginia regardless of party affiliation and that hot-button attacks and crass wedge-issue politics are not enough to defeat him. By thumping away at Mr. Kaine's stands on the death penalty and illegal immigration, Mr. Kilgore tried to play on voters' fears. He failed, and that offers a lesson that should be heeded beyond the state's borders.