Rep. Barbara Comstock (R-Va.) in her office at the Cannon building in November. (Katherine Frey/The Washington Post)

It’s just one poll — a single, imperfect snapshot of a race taken more than five months before Election Day. Even so, the first data on Virginia’s 10th Congressional District race from Monmouth University is full of very bad news for Rep. Barbara Comstock (R), and possibly for her downstate GOP colleagues as well.

The headline shows Comstock 10 percentage points behind the lesser-known Democratic nominee Jennifer Wexton among “potential voters.”

The numbers get no better for Comstock when Monmouth slices the data in different ways: She’s down 9 percentage points based on a “historical midterm model” and 11 in a version “that includes a turnout surge in areas where Pres. Donald Trump is unpopular.”

Typically, an incumbent whose numbers are below 50 percent is in trouble. For an incumbent to trail by 9 to 11 percentage points right out of the gate? That’s downright depressing.

And it gets worse.

Wexton has a 9 percentage point lead among independents. More significant, and a sign of how damaging Comstock’s primary challenger was to her general election chances, Wexton has 97 percent support among Democrats. Comstock can muster only 85 percent support among Republicans, and Wexton gets 10 percent among Republicans.

That’s enough bad news for any candidate. But the hits keep on coming.

Wexton holds leads in the district’s population centers, 57-36 percent in Fairfax County, 48-39 percent in Loudoun and 46-37 percent in Prince William.

Add it all up, and throw in Comstock’s tenuous leads in Winchester and points west, and it looks like Comstock should start updating her resume.

But before Democrats prepare the victory party, they need to keep in mind that 59 percent of poll respondents had “no opinion” on Wexton. She’s still an unknown quantity, despite the competitive and costly Democratic primary.

That gives Comstock an opening. She’s raised roughly three times more money than Wexton — and she will raise much, much more. A lot of that cash will be used to define Wexton in voters’ minds. It won’t be pretty. Many Northern Virginia residents may be tempted to smash their TVs before it’s all done.

Exploiting Wexton’s limited name recognition will be Comstock’s best chance to survive.

Her downstate colleagues, however, do not share either Comstock’s campaign abilities or her fundraising prowess. The Monmouth numbers indicate incumbents such as Reps. Scott Taylor in the 2nd and Dave Brat in the 7th may have much tougher campaigns ahead of them than were apparent even a month ago.

The big drag for them is same as it was for Ed Gillespie a year ago: President Trump.

Monmouth’s Patrick Murray said Trump is “creating a significant drag for Comstock.”

It’s exactly the sort of drag Brat will have to contend with in the 7th.  While he still has strength in the 7th’s more rural counties, the population centers in Henrico and Chesterfield — which were always going to be troublesome — may be even worse than imagined.

The imperfect cue comes from Comstock’s results in the GOP strongholds of Clarke and Frederick counties, as well as Winchester. Comstock has a 2-point edge there, in Trump country.

What might the numbers look like for Brat in his own slice of Trump country — Goochland, Orange, Culpeper and so on?

If some future poll of the 7th shows Brat weak in any of those areas, he won’t have a rural redoubt to save him from a suburban wave.

That, of course, is highly speculative. Comstock’s numbers can and will change — and she will gain ground. Likewise, Brat and Taylor, whose district has long been on the Democratic Congressional Campaign Committee’s target list, will see their races take any number of turns over the next several months.

But the first batch of data isn’t promising. And for those tempted to dismiss Monmouth’s data entirely? On the page discussing the 10th District results is a link to a Nov. 6 poll of the governor’s race. It showed Democratic nominee Ralph Northam ahead by 2 points.

He won by 9.