Democratic presidential candidate Hillary Clinton will try to mend her badly wounded campaign in a debate on Thursday with rival Bernie Sanders, an encounter many of her donors said would allow her to play a role that suits her – embattled underdog.

After her embarrassing 22-point loss to Sanders in New Hampshire’s presidential nominating contest, Clinton headed back on Wednesday to New York, where her campaign is based, to confer with top advisers and prepare for the face-off with Sanders, set for 9 p.m. in Milwaukee.

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Her campaign has denied reports that Clinton is considering a shakeup of her staff, but aides acknowledged that adding new staff was a possibility.

Several among Clinton’s wide circle of donors told Reuters they believed her surprisingly large loss in New Hampshire would ultimately bring out the fighter in her.

This would help to battle-test her, both for the contests ahead in her party’s nomination process and to take on a Republican candidate in the Nov. 8 general election, they added.

Some donors said a growing sense of nervousness was setting in, however, especially after Sanders’ campaign reported raising more than $6 million in the 24 hours after his win.

The word "disappointed" came up several times during a conference call the campaign held on Wednesday with donors and fundraisers, said one Clinton supporter who was on the call.

Many donors said they thought one immediate task for the former secretary of state’s campaign would be to improve upon her messaging.

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Sanders, a democratic socialist U.S. senator from Vermont, has built his campaign around a promise to rein in big firms and Wall Street, while Clinton has emphasized her detailed policy proposals on issues from health care to financial reform.

Several supporters said a simpler message might bring Clinton more success in galvanizing voters.

Some donors said they would like to see Clinton retool the way she communicates her thinking to voters.

"Boil it down, be clear, be succinct, and make absolutely sure everybody knows you have a plan," said Shekar Narasimhan, a Clinton donor and managing partner at Beekman Advisors.

Sanders has called for leveling the economic playing field by breaking up the big banks, creating a single-payer Medicare-for-all health care plan and offering government-paid public college tuition.

Clinton, the prohibitive front-runner in the race for months, barely beat Sanders last week in Iowa and lost decisively in New Hampshire, both states with nearly all-white populations, in the first two nominating contests.

The race now moves to Nevada, South Carolina and other more diverse states with more black and Hispanic voters, who, polls show, have been more favorable to Clinton so far.

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The shift raises the stakes for Thursday’s debate. When the two took the stage last week for their first one-on-one encounter of the campaign, they clashed sharply over their progressive credentials.

Some of Clinton's top donors said they thought she has performed well under pressure, as during her 11 hours of testimony to a congressional panel investigating the 2012 attacks in Benghazi, Libya, and in the grueling 2008 nominating battle she lost to Barack Obama.

"The idea that there’s some kind of panic is completely overblown," said major Democratic fundraiser and Clinton supporter Karin Birkelund.

"It’s really, really early – way too early – in the process, and these states don’t matter that much."