Mike Gravel, the 89-year-old iconoclastic former senator from Alaska, is ending his quixotic presidential campaign. Gravel's exit from the presidential race was announced on his Twitter page, which is managed by two teenagers from New York, David Oks and Henry Williams.

"The DNC kept us off the stage tonight even though we qualified, but the #Gravelanche is not over. We're gonna keep going. As the campaign ends, we're going to help build institutions on the left which can grow power, shape policy, and create strong activists for the long haul," said a tweet posted to Gravel's Twitter account on Wednesday.

Gravel had technically received contributions from enough unique donors to qualify for the second Democratic debate at the end of July, but because the number of candidates permitted to appear at the debate was capped at 20. The DNC used its tiebreaker rules, which gave preference to candidates who met the polling threshold over those who qualified via donors, leaving Gravel out of the group.

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A second tweet on Gravel's account said that the campaign is donating its funds to charity and forming the Gravel Institute, a "leftist think tank." This institute will release policy papers with a focus on "ending the American empire," "reforming our Democracy," "direct action by elected officials to end injustice and suffering."

A final tweet on Gravel's account announced that Oks and Williams will be doing a fellowship at Jacobin Magazine, a left-leaning publication.

"We need to keep up Mike's fight until the wars are over, until no one is too poor to live, until the people's voice is heard," the final tweet said.

The press secretary for the Gravel campaign, Marlon Ettinger, told Splinter News that Tulsi Gabbard was "courting" Gravel for his endorsement.

Gravel's campaign also told ABC News that the senator was also considering endorsing Bernie Sanders, Elizabeth Warren and Marianne Williamson.