A new poll shows Pramila Jayapal maintaining her lead over Brady Walkinshaw in the race to represent Seattle in Congress. 

How can Washington State Representative Brady Walkinshaw possibly win a seat in Congress? That's the question you're left asking after looking at all the conventional predictors in the race for the 7th Congressional District, where Walkinshaw is facing state Senator Pramila Jayapal.

Jayapal beat Walkinshaw handily in the primary, even in his own district. She leads him in fundraising. And a new poll released by Jayapal's campaign shows her up by 14 points headed toward the general election.

The Jayapal-funded poll asked 500 likely voters in mid-August whether they would vote for Jayapal or Walkinshaw if the election were held that day. Forty-three percent said Jayapal, 29 percent said Walkinshaw, and the rest were undecided.

The Jayapal campaign declined to release the full detailed results of the survey, which also included testing of campaign messaging, but released a memo of highlights from the polling firm, GBA Strategies. Jayapal leads "in every region of the district" with voters of all ages, according to the memo. She leads by 19 points with voters younger than 50.

In the August primary election, Jayapal won about 42 percent of the vote and Walkinshaw took about 21 percent. Jayapal beat Walkinshaw not only across the congressional district, but also in the 43rd state legislative district covering Capitol Hill, which Walkinshaw represents in the state house. There, Jayapal won 50 percent of the vote and Walkinshaw won just 29 percent, according to data from the secretary of state's office.

Soon after the August primary, Walkinshaw got a boost when the third main contender in the race, King County Council member Joe McDermott, endorsed him. That was a good sign for Walkinshaw. If McDermott's supporters followed his advice, it could bolster Walkinshaw's numbers. But the new polling results call into question just how helpful that endorsement will be. According to the polling firm, 59 percent of McDermott voters surveyed said they now support Jayapal.

"Bottom line," reads the polling memo, "Pramila Jayapal is in a very strong position to win in November."

Both candidates are Democrats. Jayapal, who has been endorsed by former presidential hopeful Bernie Sanders and local trans rights activist Danni Askini, has built her campaign around her reputation as a firebrand progressive...