VIRGINIA ATTORNEY General Ken Cuccinelli II’s 11th-hour attempt to torpedo the landmark state transportation funding plan enacted in Richmond this year put him at odds with leaders of his own party, including Gov. Robert F. McDonnell. For Mr. Cuccinelli, now the Republican nominee for governor, it was not the first attempt to blow up a transportation initiative critical to Virginia’s future.

Mr. Cuccinelli, formerly a state senator from Fairfax County, has long opposed Metro’s Silver Line extension to Dulles airport. That project is expected to bring thousands of jobs to Northern Virginia and spur the redevelopment of Tysons Corner, the biggest employment center in the state.

The Silver Line is expected to cost nearly $6 billion. Yet virtually every statewide elected official, plus Northern Virginia’s congressmen — Republicans and Democrats — have supported it. Everyone, that is, except Mr. Cuccinelli.

The Democratic candidate for governor, Terry McAuliffe, made an issue of Mr. Cuccinelli’s obstructionism the other day, citing his stated hope, in 2011, that Loudoun County, one of the line’s funding partners, would withdraw from the project and “kill” it. (In response, Mr. Cuccinelli’s campaign tried to confuse the issue, suggesting the Silver Line is some sort of giveaway to labor interests, which it isn’t.)

Loudoun’s all-Republican board of supervisors stayed the course, ignoring Mr. Cuccinelli for the sound reason that the county is likely to reap a $25 billion windfall from the extension, according to Stephen Fuller, a respected economist who heads George Mason University’s Center for Regional Analysis.

Were it up to Mr. Cuccinelli, the state would never have raised an additional dime for transportation. His position — that any new funding for roads and rails should be cannibalized from other parts of Virginia’s budget — would have meant taking money from schools, police departments, parks, the mentally ill and dozens of other core government services. It was a political non-starter, but it was Mr. Cuccinelli’s only proposal.

At times, Mr. Cuccinelli has said he regards bus rapid transit — dedicated bus lanes with frequent service — as a preferable option to the Silver Line. But virtually no one believes that BRT could rival Metro as an engine for economic growth, let alone as a catalyst for the revitalization of Tysons Corner.

Similarly, in the same breath as he dismisses the Silver Line as a “boondoggle,” Mr. Cuccinelli suggests that local governments be given more leeway to devise their own transportation solutions. But he neglects to mention what means he would devise for localities to generate revenue to do so. In Mr. Cuccinelli’s transportation policy, ideology trumps practicality and Virginia’s long-term prospects — like the daily lives of its commuters — are a secondary priority.