Three other candidates are very close: The former housing secretary Julián Castro and the entrepreneur Andrew Yang have surpassed 130,000 donations and each have three of the four qualifying polls they need, while Senator Amy Klobuchar of Minnesota has met the polling threshold and has about 120,000 donors.

Beyond them, only three candidates have even a single qualifying poll to their name: the impeachment activist Tom Steyer (2 polls), Representative Tulsi Gabbard of Hawaii (1) and former Gov. John Hickenlooper of Colorado (1).