From time to time, Gov. Tim Kaine of Virginia takes political guidance from his father-in-law, Linwood Holton, which makes sense -- Holton, 83, once held the office Kaine now occupies. Holton's advice often includes a reminder of the emancipating effect of the state's unique one-term governorship. Since running for reelection isn't an option, Virginia governors needn't sweat the politics as much as their counterparts in other states (though of course some do).

Kaine may be even more liberated than his predecessors because, in his case, the usual doors to political advancement look shut for now; his first plausible shot at running for the Senate is probably seven years off, at best. That may partly explain his tough line against the transportation funding package that Virginia's General Assembly approved last weekend.

The first bill in a generation to yield substantial new money for roads and transit, it has been hailed by its Republican sponsors as a triumph and embraced by some Northern Virginia business groups as deliverance from the region's slow-motion transportation meltdown. In fact, it is a weaselly plan that offloads the unpleasant business of raising taxes onto local officials, most of them Democrats, while borrowing heavily and shortchanging public education, health care and public safety to pay off the debt.

For Kaine, who tried and failed twice last year to forge a major tax overhaul to fund transportation, the path of least resistance would be to declare victory. After all, it's the governor, not the Republican foot-draggers in the General Assembly, who's done everything but hold a prayer breakfast on I-95 at rush hour to get a transportation package passed. It was only the shock therapy of George Allen's defeat in last fall's Senate race, coupled with Kaine's all-too-plausible threat to target individual Republican lawmakers who have blocked transportation deals in the past, that forced the GOP finally to fashion its own feeble proposal.

Yet, much as he'd like a victory, he doesn't need one to run on -- because there's nothing to run for anytime soon. "I'm not looking to be unpopular," the governor told me. "But at the end of the day some of the normal politics don't matter as much."

So, faced with a badly flawed bill, the governor is pulling no punches. He's called it "bogus" in public (and worse in private) and is threatening a veto unless the House of Delegates agrees to fixes he will propose, which are bound to include steeper taxes.

The governor is an exceptionally smart man, intellectually nimble, confident and politically adept. But it's tough to say he's likely to prevail in a smackdown with the legislature's conservative Republicans.

If his suggested amendments raise statewide revenue much -- that is, if they do the sensible thing by investing more in roads and rail without raiding other state services -- they'll be squashed in the staunchly anti-tax House. Then the governor will face the choice of vetoing the first major transportation funding legislation in 21 years or signing a bill that he has rightly pilloried.

In this game of chicken, the threat of a veto is useful; without it, Kaine lacks any credible leverage to make the House swallow his amendments. But a veto would be a tough sell, and potentially a costly one. Every seat in the state legislature will be on the ballot this fall, and Republicans clearly relish the idea of running against a governor who spurned new money for transportation after seeking it for a year. A handful or more of vulnerable Democrats could lose their seats.

And from the Democrats' perspective, the sound-bite wars that would follow a veto would not be pretty. Already, a Republican ad campaign aimed at Kaine taunts: "Start solving problems. Stop playing politics." Just try reducing the Democrats' arguments -- about sapping other state services, or the perils of debt financing, or the inequity of regional taxes -- to zingy one-liners. Who cares if they're right if they're losers?

Kaine has had some victories in his first 14 months in office. This year he got legislation passed to remove Virginia's poorest people from the state's tax rolls, 350,000 residents in the lowest 10 percent of wage earners. He would also dearly love a signature achievement -- a decent transportation bill -- if he can get one. Still, this is a governor who campaigned strongly against the same-sex marriage amendment on last fall's state ballot, a lost cause from the outset. He's not allergic to a fight on principle or to a showdown over a bad bill.

No Virginia governor has found fresh revenue for road-building since 1986, and the sorry results are on daily display in bumper-to-bumper traffic. As it happens, the man who managed that feat, Gerald Baliles, had something in common with Kaine. He was the last Virginia governor who had no real plans to run for higher office.

The writer is a member of the editorial page staff. His e-mail address is hockstaderl@washpost.com.