THE RESULTS of Virginia's gubernatorial primaries this spring, in which Democrat Ralph Northam and Republican Ed Gillespie each beat more extreme party challengers, looked promising for the commonwealth's voters, whose record of electing more or less pragmatic candidates in statewide races is well established. Both men are able, widely respected and have had impressive careers, including in business and politics — Mr. Northam, the current lieutenant governor, as an Army veteran and pediatric neurologist; Mr. Gillespie as a Republican operative and lobbyist.

Mr. Northam, whose knack for working across the aisle once prompted Republicans in the state Senate to ask him to switch parties, mounted a campaign largely true to his reputation for decency and good sense. Unfortunately, Mr. Gillespie chose a different path. Faced with a choice of highlighting his undeniable command of policy or pandering to vile and racially inflammatory tendencies in his party's base, the Republican opted for the latter. In so doing, he shocked even some admirers.

It is not that Mr. Northam is qualified and Mr. Gillespie unqualified. It is that Mr. Northam can convincingly promise to be governor for all Virginians, while Mr. Gillespie, even while asserting the same, has disqualified himself from any such credible claim. We support Mr. Northam.

Having used massive TV advertising buys to whip up the fears and hatreds of his party's extremists — by equating illegal immigrants with violent Hispanic gangs; by embracing Confederate monuments weeks after they were the rallying cause for neo-Nazis and white supremacists in Charlottesville; by distorting the facts on rights restoration for a convicted sex offender — the Republican candidate has swapped his cloak as a problem-solver for a demagogue's mantle. Having chosen to campaign as a divider, Mr. Gillespie's chances of governing as a uniter are dim.

It is possible that Mr. Gillespie's descent into gutter tactics will pay off at the polls Nov. 7. If that's the case, and Virginia Republicans rejoice on election night, what they will really be celebrating is a victory of divisiveness and the ascent of wedge politics in a state once known for comity.

On policy, both men have records reflecting their own party's mainstream priorities; we have agreements and disagreements with each. However, while Mr. Northam has maintained relatively consistent stances, Mr. Gillespie, trying to play to both right-wing and centrist factions in the GOP, has hopscotched from one side to the other on many issues.

He attacked Virginia's 2013 landmark transportation bill, the first to raise new revenue for deteriorating state roads in a quarter-century, branding it as a massive tax hike backed by Mr. Northam, before he was for keeping it, as a means of securing the endorsement of a business group in Northern Virginia. On transgender bathrooms, he skewered the idea that girls would share a restroom with boys who identify as girls, then pivoted, again to court a business group's support, by saying he'd oppose legislation like North Carolina's banning transgender bathrooms. He's similarly straddled on providing in-state tuition subsidies at public universities for "dreamers" — undocumented immigrants brought to the United States as children — telling a campaign rally he'd oppose it while suggesting to us he had no position on the issue.

Before he tilted toward incendiary social issues, the centerpiece of Mr. Gillespie's campaign platform was a pie-in-the-sky tax cut that would slash state revenue, by about $1.4 billion from an annual tax-supported budget of $20 billion — even as he proposed dozens of costly new programs and initiatives. Asked to name state programs he might cut to pay for his tax plan, Mr. Gillespie did not name any.

We have areas of disagreement with Mr. Northam as well. He too proposes a tax cut, though a more modest one — scrapping the grocery tax for low-income Virginians — and, like Mr. Gillespie, offers no realistic plan to pay for it. Mr. Northam would kill Virginia's current standardized tests in public schools, on grounds that they are excessive and unfair to disadvantaged students. Yet he has no alternative that would measure achievement or ensure that schools remain accountable. (Mr. Gillespie, for his part, offers doublespeak on the question of testing and accountability, though he is more determined to broaden educational options by expanding the state's paltry roster of charter schools.)

On climate change, Mr. Northam would continue Gov. Terry McAuliffe's (D) innovative initiative promoting low-carbon energy technologies with efficient, market-based policies. Mr. Gillespie has condemned the plan, in keeping with his and his party's effort to promote coal, an outdated, dirty energy source that has struggled to compete in recent years.

In the down-ticket races, which feature four lawyers, the choices are equally clear. For lieutenant governor, Democrat Justin Fairfax, the much better choice, is a bright, competent, well-versed former federal prosecutor turned corporate attorney. His opponent, State Sen. Jill Holtzman Vogel (R-Fauquier), opposed the 2013 transportation bill, then acknowledged it did wonders for her district. Her campaign website touts her sponsorship of radical tea party legislation that would have empowered states to overturn federal laws and regulations they disliked; now she seems utterly unaware of the bill. She objected to what she called President Barack Obama's "heavy-handed" federal mandate on transgender bathrooms, but sponsored a far more heavy-handed measure that would have forced most women seeking abortions to undergo mandatory vaginal ultrasounds.

For attorney general, we favor the incumbent, Democrat Mark Herring. Mr. Herring won the office four years ago by assailing the partisanship of his arch-conservative Republican predecessor, Ken Cuccinelli II. Once in office, he was attacked for being almost equally activist as a champion of leftist causes. Yet Mr. Herring plausibly argued that his highest-profile decision — refusing to represent the state, his client, in a lawsuit challenging its ban on same-sex marriage — was a principled decision tantamount to declining to defend segregated schools in mid-20th-century Virginia. The Republican candidate, John Adams, an intelligent corporate lawyer, attacks Mr. Herring for spurning his own client, acknowledges that he, too, would have refused to defend segregation; but discounts the analogy. Advantage Mr. Herring.