Serve America and the candidates have received at least some contributions from the effort, but there is no way to gauge whether it spurred people to register or vote.

“It’s not targeted to any one particular district or group of people,” Mr. Moulton said. “We just want Americans to know that there are amazing leaders running for office and these women are such shining examples of that.”

The only way the ad can actually reach television would be through another group, like the Democratic Party, deciding to sponsor it.

Mr. Moulton said the party could do more to support the candidates featured in the ads. “I believe that as Democrats, if we want to start winning again, we need to start leading again,” he said. “These are tough races. Yet these are extraordinary candidates in really tough districts.”

But at least some of the candidates are hardly struggling for campaign funds. Amy McGrath, a former Marine combat aviator and Democratic House candidate in Kentucky, and Abigail Spanberger, a former C.I.A. operative and candidate in Virginia, each raised more than $3.6 million in the last quarter. Another, Chrissy Houlahan, running in Pennsylvania’s redrawn Sixth District, is considered a strong favorite, with or without the help.

Veteran political strategists said the video had a collective power, using a patriotic appeal to vote, without any overt partisan pitch. There is also a clear tonal diversion from the harshly negative ads that most voters are seeing in the closing days before the election.

“If Democrats are going to take back the House, if all you do is slam Republicans, that’s probably not going to get you over the line, particularly at a time like this when so viciously negative,” said Paul Begala, a Democratic strategist. “Showing women who are patriots, who are less partisan, and who are clearly motivated by public interest, I just think it’s great and exactly what people want.

“It’s a balm for the soul when everyone else is throwing bombs,” he added.

And it is not an accident that all of the candidates featured in the ad are women, in a year with a record number of women running for office. “Very powerful message that works on multiple levels,” said Stuart Stevens, a Republican political consultant who has worked on dozens of Senate and presidential campaigns. “As much about voting for women as voting for those who have served.”