It also could lead to a sordid sideshow over allegations that the FBI's key witness against Stevens had sex with an underage girl.
Powell and the lawmakers were listed among more than 200 potential witnesses identified by a federal judge Monday as jury selection began in the Alaska Republican's trial. Opening arguments could begin Wednesday.
Also named as possible witnesses were Democratic Sen. Daniel Inouye of Hawaii and Republican Sen. Orrin Hatch of Utah.
Stevens is charged with lying on Senate financial disclosure forms about home renovations and other gifts he received from Bill Allen, the founder of powerful oil contractor VECO Corp.
The trial could offer a glimpse at the favors and gifts bestowed on Capitol Hill lawmakers and the process by which they are disclosed - or concealed.
U.S. District Judge Emmet G. Sullivan did not say which witnesses were called by the government, and which might be called by Stevens. But Stevens has described Powell as one of his closest friends. The lawmakers could testify about Stevens' personality or about the difficulties of keeping track of what services must be disclosed on Senate forms.
Also on the list of potential witnesses were figures in a now-suspended investigation into whether Allen had sex with an underage girl in the 1990s. He was never charged and has denied any wrongdoing in that case.
Allen, who has pleaded guilty to corruption charges and is the FBI's star witness, is expected to testify that he lavished Stevens with gifts and favors. Stevens' attorneys could try to use the sex case to discredit Allen, whom Stevens once counted among his friends.
Stevens, wearing a blue tie and an American flag lapel pin, remained expressionless in court Monday and looked intently at the 184 potential jurors. He said nothing but "Good morning" upon leaving court.
Stevens, a political patriarch in Alaska since before statehood, is fighting for his political life. He is in a tough race for re-election against Anchorage Mayor Mark Begich, a Democrat. The longtime GOP icon will have to stay in Washington during the trial, while Begich is free to campaign around Alaska.