It was a distinguished group of lawyers that orchestrated the discreet fund-raiser in Washington in mid-November.

Vernon E. Jordan Jr., the counselor to Democratic presidents, and Eric H. Holder Jr., the former attorney general, were listed as hosts on the invitation. Over an assortment of Mexican dishes, in a home not far from the National Cathedral, Senators Kamala Harris of California and Catherine Cortez Masto of Nevada, both former prosecutors, enthused about the prospect of electing another Democrat to the Senate.

Beaming in from Alabama to thank his new donors — seated beside his wife, Louise, on a halting video stream — was Doug Jones.

For Mr. Jones, the Democratic nominee in a special election for the Senate, the event confirmed his dizzying emergence in national politics. Days earlier, his Republican opponent, Roy S. Moore, had been hit with allegations of child sex abuse that threatened to upend his campaign and give Mr. Jones an unexpected shot at victory.