Ms. Moser, whose husband was the videographer for President Barack Obama, skewed a little farther left. Her work history was spottier: She has been a freelance writer. After Mr. Trump’s victory, she created Daily Action, a service that allowed the grief-stricken to barrage their public servants in Washington with angry texts. All three candidates were native Houstonians, though Ms. Moser came home from Washington to run.

By the end of the third quarter of 2017, Mr. Triantaphyllis had raised the most money — more than Mr. Culberson. Ms. Fletcher came in second and Ms. Moser third. At the same time, Ms. Moser, who somewhat resembles a taller and younger Carol Burnett, was more colorful in person and better at grass-roots organizing than her competitors. If her politics were a little squishy, she was more entertaining — supporters could take a spin class with #MeToo’s Alyssa Milano!

It wasn’t hard to figure out how threatening that could be, especially to the old-line Clinton Democrats who lost to Mr. Obama in 2008 and remembered the betrayal of Bernie Sanders in 2016. Those people undoubtedly influenced the political action committee Emily’s List to endorse Ms. Fletcher — and should have listened to the grumbling among female voters here, who thought the organization should not have chosen between two female abortion-rights supporters.

Then came the D.C.C.C., with its high-stakes gamble of attacking Ms. Moser on its website. Maybe it believed, along with The Houston Chronicle, that Ms. Moser was too liberal to beat Mr. Culberson. (The paper endorsed Ms. Fletcher and another Democratic candidate, an oncologist.) Maybe the committee thought its gripes were legitimate — it complained that Ms. Moser was a “Washington insider” who had used her husband’s firm as her political consultants. But the first wasn’t true, and the second showed only that her husband worked cheap. Ms. Moser stated publicly she wouldn’t want to live in Paris, Tex.? Wow. Most urban Texans wouldn’t either.

Besides, there is nothing Texans hate more than East Coast political operatives meddling in their business. Especially those who don’t know anything about Texas.

Virtually overnight, the story of interference from real Washington insiders went viral, and Ms. Moser became a glorious martyr, quoting Michelle Obama (“When they go low …”). Her profile is skyrocketing, her fund-raising is booming. And no doubt John Culberson is ecstatic about the Democrats being in disarray.

Note to the D.C.C.C.: Next time you think about sticking your nose where it doesn’t belong, try believing in the democratic process instead.