Democratic mega-donors for former Vice President Joe Biden are starting to worry after his disastrous performances in Iowa and New Hampshire, according to a report.

“Even if we stay active for the next two races after another big loss, I suspect the remaining air will leak out of the balloon before Super Tuesday,” one Biden fundraiser told CNBC.

That same donor, who requested not to be identified but has known the former vice president for over a decade, said that failure in New Hampshire indicates that he will face disaster come Super Tuesday on March 3, when 14 states plus American Samoa and the Democrats Abroad will put a third of all delegates in play, including California’s 415 and Texas’ 228.

Multiple bundlers for the one-time front-runner told the network that members of their donor networks had already begun calling them to say that Biden’s weakened status after New Hampshire and Iowa “looks like an insurmountable hurdle.”

“These donors are also saying that they will stop backing Biden’s campaign if he continues underperforming,” the report said.

Some donors said they still have some optimism about Biden’s ability to perform, adding the former VP is in a strong position to make a comeback in South Carolina.

The Biden camp has now essentially bet the house on the Feb. 29 primary in South Carolina, where Biden has enjoyed the most support from black Democratic voters thus far.

He leads his competitors in the state handily with 31 percent support, according to a Real Clear Politics average.

Billionaire businessman Tom Steyer polls in second with 18.5 percent in the state.