WASHINGTON — Barack Obama told a potential donor to his campaign that Hillary Rodham Clinton is on his list of possible vice presidential running mates, but that her husband's status as a former president presents a "complication."

Jill Iscol, a Democratic donor and ardent supporter of Clinton's presidential campaign, said Obama reached out to her because he heard that she was unhappy about the way the New York senator had been treated by the Democratic Party and the media.

Iscol turned their phone conversation Thursday to the vice presidency — something the Obama campaign has refused to discuss publicly. She said she told him that Clinton would be his best running mate.

Obama replied that she is on his list, Iscol recounted. He said it would be a mistake not to have her on such a list. But he also confided that he was thinking through a potential "complication" — Bill Clinton.

"He said once you're a president, even if you're a former president, you're always a president," Iscol said.

Still, Iscol hung up believing Hillary Clinton had a shot. Obama didn't say that Bill Clinton would be a disqualifying factor, but he conveyed that he needed to grapple with what it would mean to have a former president as second spouse.

Obama also was willing to hear Iscol make the argument for Hillary as No. 2.

"I said nobody has been vetted the way she has been vetted," Iscol said. "We need to pick the most qualified, wisest, smartest, experienced person to serve our country alongside of Barack Obama. And I think it's Hillary Clinton. We need her, and the party needs her, and it will be a ticket that will steamroll its way to the White House."