Key fundraisers in former Vice President Joe Biden’s struggling campaign have left to support former New York City mayor Mike Bloomberg’s campaign. 

The news comes after concerns within Biden’s donors emerged over whether or not he’d be able to beat Sen. Bernie Sanders (I-Vermont), a self-described democratic socialist.

Jon Henes, a partner at the law firm Kirkland & Ellis, reportedly told people close to him that he was switching over to Bloomberg’s campaign according to people close to him. The same sources reported that he is only one of almost a dozen donors who’s switched allegiance. 

Biden struggled in Iowa and New Hampshire, and is falling behind in the polls. Bloomberg, on the other hand, is steadily climbing and is in third place in national polls.