(CNN) As Sen. Cory Booker prepares to take the stage this week for the CNN Democratic debate in Detroit, his campaign tells CNN that he has qualified to participate in the third debate coming up this fall.

Booker surpassed the higher threshold of 130,000 unique donors, his campaign said Monday, after having previously met the polling requirements for the debate , slated for September. Booker's campaign said more than a quarter of those donors contributed since the first June debate, when he dominated in speaking time among the candidates.

"We're building this campaign the right way, brick by brick from the grassroots up, and we're seeing the results of that strategy as we continue to build momentum," said Booker's campaign manager Addisu Demissie. "We're grateful to the tens of thousands of Americans who have chipped in to ensure Cory's voice will be heard in the Democratic debates this fall, and who believe in Cory's uplifting vision of building a more fair and just country for everyone."

The news gives Booker a burst of momentum at an opportune moment, just as he is set to take the debate stage Wednesday with former Vice President Joe Biden , the current Democratic frontrunner, and other rivals. And, if the recent public back-and-forth between Biden and Booker is any indication, it could be a contentious meeting.

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