IT’S NO secret that many Virginia voters have expressed disappointment with both major party candidates for governor on next month’s ballot. Little wonder: Given the doubts their own parties’ activists have voiced about Terry McAuliffe, the Democrat, and Attorney General Ken Cuccinelli II, the Republican, how are the rest of us supposed to feel?

Still, pining for different candidates is a waste of time, and staying home on Election Day is irresponsible. Whatever the candidates’ failings, they offer a stark and consequential choice that boils down to this: Will Virginia stick to its long tradition of moderate, pragmatic governance, or will it veer off into an ideological adventure at the behest of one of Richmond’s most polarizing and provocative public figures of the last decade?

We share Virginians’ misgivings about the candidates, but for us the decision is clear: Terry McAuliffe, his flaws notwithstanding, represents continuity in a state that has been well served by comity, compromise and political coexistence between the parties. Mr. Cuccinelli, the most partisan, truculent and doctrinaire attorney general in memory, represents an assault on those same customs. That’s why a number of prominent fellow Republicans, including Lt. Gov. Bill Bolling, have refused to support him, in an astonishing display of intra-party dissent.

Mr. McAuliffe, who is nothing if not a deal-maker, holds out the credible promise that Virginia will remain open, tolerant and pragmatic, friendly to business and committed to job growth. That is critical in the face of sequestration and other austerity measures in a state whose economy is heavily dependent on federal spending.

In contrast to his scattershot campaign for the Democratic nomination for governor four years ago, Mr. McAuliffe has run a focused campaign, locking up the nomination on the strength of a peripatetic outreach effort that took him to every corner of the state.

There is no disguising that Mr. McAuliffe, a self-described wheeler-dealer who burst on to the national stage as a prodigious fundraiser for Bill Clinton in the 1990s, lacks the close engagement with policy possessed by Virginia’s recent governors. The ultimate political insider, his stock in trade has been playing the angles where access and profit intersect.

Nonetheless, as a candidate for governor Mr. McAuliffe has taken sensible stands on key issues, and he has had the political savvy to stay mostly on message. Critically, he embraced the transportation funding bill enacted by a bipartisan majority of the General Assembly this year, a measure that will ensure that the state’s roads and rails keep pace with a 21st-century economy.

That stance, in line with Gov. Robert F. McDonnell’s, took courage; at its core is support for a substantial tax increase. Tellingly, Mr. Cuccinelli, who for a decade opposed every significant, politically viable effort to rescue the state’s crumbling transportation systems, did his best to subvert the bill. Mr. Cuccinelli would have Virginians believe that roads can be built on a wing and a prayer; Mr. McAuliffe had the spine to say what moderate Republicans and Democrats finally agreed on: that a modern transportation network cannot be built for free.

As a candidate, Mr. McAuliffe has pushed for spending more on community colleges and expanding education for preschoolers, but he’s been vague about the cost of those programs. He argues that expanding Medicaid, with the federal government bearing most of the cost, would yield a windfall for the state. That’s possible — higher Medicaid spending by Washington could save states money and generate jobs — but the money is unlikely to be sustainable.

Still, it is a more realistic economic program than Mr. Cuccinelli’s, which promises huge tax cuts without any realistic strategy to pay for them. Mr. Cuccinelli argues gauzily that he can slash $1.4 billion in taxes on business and individuals and make up the income by eliminating unspecified tax breaks. That’s fantasy. By refusing to say whose tax breaks he would eliminate, and whose interests he would attack, the Cuccinelli plan is also an exercise in evasion.

Mr. Cuccinelli’s real promise is a vision of the government’s role that differs radically not only from Mr. McAuliffe’s but from that of most previous Virginia governors.

In this campaign, he has emphasized the economy, but his sudden devotion to the practicalities of job creation is not credible. For more than a decade, he compiled a well-documented record concerned first and foremost with social issues, not economic ones. In the state Senate, he was an early sponsor of the “personhood” amendment, which defined life from the moment of fertilization and would have provided a springboard for legal attacks on contraception. He opposed common-sense gun-control and traffic-safety measures.

As attorney general, Mr. Cuccinelli waged a long and ultimately fruitless jihad against Michael Mann, a University of Virginia climate scientist, and filed a petition challenging the Environmental Protection Agency’s finding that global warming poses a threat to humans. He showily contrived to become the first state’s attorney general to sue the federal government over Obamacare.

To Mr. Cuccinelli, the world is full of outrages that he would use government’s big stick to correct: Climate-change science is a hoax perpetrated on taxpayers. Illegal immigrants should be deported, and legal ones should be denied unemployment benefits if they are fired for not speaking English on the job. Abortion clinics should be regulated out of existence. Homosexuals, who by their sexual conduct invite “nothing but self-destruction, not only physically but of their soul,” don’t merit equal protection under the law.

And now Mr. Cuccinelli says he would be focused on jobs and the economy? Don’t count on it. The far more likely scenario is that if he were to become governor, Mr. Cuccinelli would plunge Virginia into the venomous, corrosive culture wars that have paralyzed Washington.