Democratic presidential candidate former Vice President Joe Biden speaks during a campaign event at Sun City Macdonald Ranch February 14, 2020 in Henderson, Nevada. Alex Wong | Getty Images

Key fundraisers are jumping ship from Joe Biden's struggling presidential campaign to instead support Mike Bloomberg's ascending candidacy. The development comes amid growing concerns within Biden's affluent donor network that the former vice president is struggling to convince voters that he can defeat Sen. Bernie Sanders, a self-described democratic socialist, for the Democratic nomination. The financiers are also impressed with Bloomberg's self-funded operation. Jon Henes, a partner at the law firm Kirkland & Ellis, has signaled to friends that he is shifting his allegiance from Biden's campaign to Bloomberg's bid to take on President Donald Trump, according to people with direct knowledge of the matter, who declined to be named as these decisions were made in private. Henes is one of close to a dozen other Biden fundraisers who have already decided to move toward Bloomberg, these people added.