Virginia gubernatorial candidates Ralph Northam (D), left, and Ed Gillespie (R) shake hands before a Sept. 19 debate. (Bonnie Jo Mount/The Washington Post)

There are moments in a campaign when you can feel the momentum shift in the other guy’s direction. That seems to be happening in Virginia now.

With a week to go before Election Day, the shift could lead to Republican gubernatorial nominee Ed Gillespie snatching victory from Democratic nominee Ralph Northam.

The source of the change is an ad — not from the Northam campaign but from an outside group, the Latino Victory Fund.

The 60 second spot, according to The Post’s Fenit Nirappil, is airing on Spanish-language stations in the D.C. and Richmond areas. In it, a white male in a pick-up truck displaying a confederate flag and an Ed Gillespie bumper sticker chases a group of minority children. It closes with video of the tiki-torch Nazis parading on the grounds of the University of Virginia.

The ad calls on voters to reject hate, a similar message to the cringe-inducing Northam mailer that also linked Gillespie to the Nazi marchers and, for added effect, a Make American Great Again-capped Donald Trump.

Republicans immediately condemned the Latino Victory Fund ad and badgered the Northam campaign to distance itself from the content. The campaign refused to do so. “Independent groups are denouncing Ed Gillespie because he has run the most divisive, fear mongering campaign in modern history,” said Ofirah Yheskel. “It is not shocking that communities of color are scared of what his Trump-like policy positions mean for them.”

That response has heartened some Democrats, who have bristled as the Gillespie campaign unleashed a series of truth-twisting ads depicting Northam as soft on gangs and eager to restore civil rights to convicted sex offenders.

But with the Latino Victory Fund ad, the Democrats have plumbed fresh, new depths. The blowback could cost Northam dearly.

The ad’s intention is to drive up voter turnout among minorities. That’s a demographic that should favor Northam anyway. But as the New York Times reported, Northam’s campaign has had difficultly motivating this constituency, even as the GOP has seemingly gone out of its way to alienate them.

The Latino Victory Fund ad is part of that motivational effort. It uses the two-by-four of fear — using kids to grab viewers’ attention — to get those voters off the sidelines and into the voting booth.

But the ad may serve to motivate the voters Gillespie needs the most to tip the election his way: Trump supporters.

Gillespie barely squeaked by Corey A. Stewart in the June primary, in part because the section of the party that finds Stewart’s brand of identity politics appealing bought Stewart’s “establishment Ed” critique wholesale.

For months, finding a way to ease those voters’ concerns without embracing the worst views of its fringe elements dogged the Gillespie campaign. Gillespie skirted the decency line with his ads seeking to motivate them — and he fully crossed it with his MS-13 ad.

Northam appeared to have gained the upper hand with his own ad calling the Gillespie TV spots “despicable.” It was reminiscent of Tim Kaine’s response to Jerry Kilgore’s “Stanley” ad in 2005.

Enter the Latino Victory Fund. Its spot plays directly into Trump voters’ real and imagined fears of marginalization and resentment. It goes further by painting them as stars-and-bars waving racists who get their kicks terrorizing minority children.

It could be enough to convince those “never-Ed” voters to show up and vote for him anyway. Not because they like or trust Gillespie. But because the other side appears to genuinely hate them.

Nate Gonzales shifted his rating on the race from “lean Democratic” to “tilt Democratic” because of uncertainty surrounding the Northam campaign.

The Latino Victory Fund ad could very well have shifted the race further — to “tilt Republican.”