WASHINGTON – The debate over Alexander Hamilton's place on the $10 bill is turning into a saga that may be worthy of its own stage production.

The hit musical "Hamilton" provoked a wave of interest in the man who established the U.S. financial system and whose face has long decorated the note. That's propelled a concerted effort the keep him there. Now Treasury Secretary Jacob Lew is facing a backlash from women's rights activists over his remarks that suggested a possible change to his widely touted plan to put a woman on the front of the bill.

"Hell hath no fury like a woman scorned," said Lisa Maatz of the American Association of University Women. "A promise was made and it should be fulfilled."

The Treasury announced last year its intention to feature a woman on the $10 bill, possibly as one of two images or in rotation with Hamilton, Lew's recent words have cast some doubt over whether that plan is still operative.

"Alexander Hamilton is one of my heroes," Lew said in an interview with Charlie Rose on March 30. "He's not leaving our money. We're going to put a woman on the face of our currency. And this is not just about the $10 bill. This is about a whole series of bills."

A U.S. official with knowledge of the process declined to say this week whether the Treasury Department remains committed to putting a woman on the $10 note. That official and others said Lew's thinking on the issue has evolved since the initial announcement of a $10 redesign in June 2015, but they wouldn't outline the plan.

President Obama's spokesman, Josh Earnest, declined Wednesday to say whether the White House had a position and said it would be up to the Treasury Department. Obama in 2014 called putting a woman on a bill "a pretty good idea."

If the Treasury decided to keep Hamilton as the sole face of the $10, one option is to put a woman on the face of the $20, replacing former President Andrew Jackson. The politics of a Jackson swap might be easier; Jackson had been a slave owner and is not enjoying a renaissance like Hamilton. Another possibility is to make simultaneous changes to multiple denominations that would put women's images on various bills.

"It would be a mistake to back off," Maatz said of Lew. "Even if he's hemming and hawing now, I think the feedback is going to show him quickly that he needs to get back on track."

Women on 20s, the group that has led the charge to feature a woman on U.S. currency, sent a letter to Lew and U.S. Treasurer Rosie Rios on Monday asking that they fulfill the promise to put a woman on the $10 bill, said Susan Ades Stone, the group's executive director.

"Unless they're saying, 'We're going to keep Hamilton on the $10 and we're going to put a woman on the $20 and we'll issue them both at the same time,' that's not good enough," Ades Stone said.

Since the initial announcement about redesigning the $10 bill was made by Lew in June 2015, "Hamilton" has become one of the hottest shows on Broadway.