To be included in the November debate, candidates must receive donations from at least 165,000 people and must meet one of two polling requirements: They must receive either 3 percent support in four qualifying national or early-state polls, or 5 percent support in two polls in the four early-voting states — Iowa, New Hampshire, Nevada and South Carolina. The five candidates who qualified for the November debate have all passed the donor threshold and met the polling standard with the release of Tuesday’s New Hampshire poll.

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The date and location of the November debate have not been announced.

Ms. Gabbard, 38, who was a soldier in Iraq and currently serves as a major in the Hawaii Army National Guard, has made getting out of foreign wars her central campaign promise and is likely to reiterate her message in front of the national television audience that the October debates will provide.

For weeks, Ms. Gabbard was just a few polls short of making the fall debates, and as it became clear she would not be allowed to participate in the September event, her campaign began to publicly question the D.N.C.’s qualification criteria. Like some of her rivals for the nomination, Ms. Gabbard has earned 2 percent support or higher in several polls that the D.N.C. does not count toward debate qualification, and her campaign has argued vociferously that some of them should.