Former U.S. ambassador to the United Nations Nikki Haley’s new Wall Street donors closely watched her Republican debate performance Wednesday, as a first test of whether she could maintain enough momentum to take on frontrunner Donald Trump, according to people familiar with the matter.

Many of the same contributors were privately wary that Haley could successfully put away her chief competitors for second place, Florida Gov. Ron DeSantis and businessman Vivek Ramaswamy.

Haley faced an early attack from both DeSantis and Ramaswamy over her recent burst of support from Wall Street. “Nikki will cave to those big donors when it counts,” DeSantis said.

“He’s mad because those Wall Street donors used to support him, and now they support me,” Haley fired back.

In order for major donors to keep funding Haley’s campaign at a high rate, a winning debate performance was crucial, a top Haley bundler told CNBC.

Looking beyond the debate, the former South Carolina governor will need a strong showing in her home state primary Feb. 24, if she hopes to keep these wealthy donors in her camp.

“If she looks competitive in South Carolina, they will keep funding her for Super Tuesday and beyond,” said a person who attended a Wall Street heavy Haley fundraiser Monday.

Both this person and the bundler were granted anonymity in order to discuss private conversations with donors.

Nationwide, Haley trails Trump by about 50 percentage points, according to the Real Clear Politics polling average.

Haley has another big fundraiser coming up next week in Boston, according to an invitation reviewed by CNBC. Tickets are $6,600 per person.

Co-hosts include Jim Davis, the owner and chairman of New Balance, Bain Capital Private Equity senior advisor Paul Edgerley and Spencer Zwick, co-founder of Solamere Capital and former national finance chair for Utah Sen. Mitt Romney’s two presidential campaigns.