Corey Stewart (R) talks with the media in Woodbridge on July 13 after announcing that he will run against Sen. Tim Kaine (D-Va.) for the Senate. (Jahi Chikwendiu/The Washington Post)

COREY STEWART, the bottom-feeding local official whose campaign bombast, nativist venom and red-meat, race-tinged pandering to Virginia’s Republican base nearly earned him the GOP gubernatorial nomination last month, has announced his bid to unseat U.S. Sen. Tim Kaine (D). If ever there were a contest pitting loathsome demagoguery against principled decency, this would be it.

Just in case any Virginians remained cloudy about the content of his character, Mr. Stewart swiftly disabused them: “I’m going to run a very vicious and ruthless campaign,” he declared, inspiringly. “No holds barred. The type of campaign we haven’t seen in Virginia in a generation.”

No surprises there. Mr. Stewart, chairman of the Prince William Board of County Supervisors, has long been a garden-variety provocateur who delights in grabbing headlines with the most noxious slams, slights and sound bites that occur to him, all the while winking at political journalists that he doesn’t quite mean it and that his tactics are cunningly devised in service to his depthless ambition. One moment he’s sneering at “establishment pukes” and courting white supremacists by draping himself in the Confederate battle flag; the next he’s trading insider chitchat with mainstream reporters about attracting “earned media” and the latest poll numbers.

Mr. Vicious, we mean Mr. Stewart, may imagine himself clever for having bagged 42.5 percent of the primary vote in an off-year election by using buzzwords (“culture,” “heritage”) designed to trade on ethnic, nationalist and racial resentments. In fact, mainstream Virginia voters, including Republicans who opposed him in the primary, are unlikely to forget his gutter tactics.

Mr. Stewart was Virginia campaign chairman for a few months last year for Donald Trump — a natural alliance until even the Trump campaign grew sick of his stunts and dumped him. Having run for years for every plausible office in Virginia, and some that were less than plausible, he wasted no time in launching his primary campaign to challenge Ed Gillespie, a buttoned-down former Republican National Committee chairman and White House adviser to George W. Bush for whom Mr. Stewart didn’t bother masking his contempt.

In the meantime, he made it clear that his grasp of state policy questions was impressionistic, at best. Among his most risible ideas was a proposal to phase out Virginia’s income tax, which accounts for two-thirds of general fund revenue, meaning the state would have no means to pay for schools, colleges, prisons, parks, roads, bridges and tunnels.

He lost, but not by much — just over one percentage point — after having tirelessly appealed to the Republicans’ more racist instincts by posing as a champion of Confederate symbols, an issue for which he conjured a newfound passion. (Mr. Stewart is originally from Minnesota.)

Considering he has served notice that he intends to run a “vicious” race next year for Senate, it’s fair to wonder to what new lows he may descend in attacking Mr. Kaine, whose constant civility and substantive grasp of policy are certain to offend Mr. Stewart. We hope the Republican Party can come up with a more plausible, and honorable, challenger.