By Cathy Burke   |   Wednesday, 26 Aug 2015

Former President Bill Clinton is reportedly "very agitated" by Vice President Joe Biden's potential challenge to Hillary Clinton for the Democratic presidential nomination.

With controversy swirling over Hillary Clinton's use of a personal email server while serving as Secretary of State — and amid a strong challenge from independent Vermont Sen. Bernie Sanders on the campaign trail — the Clinton campaign is closely tracking Biden’s activities, Politico reports.

Citing an unnamed source who's spoken with the former president in the past two weeks, Politico reports Bill Clinton in particular is "very agitated" by a possible — but still unannounced — Biden entry into the White House race.

But not Hillary Clinton, Politico reports. Some of her top campaign officials even think a Biden run would energize an otherwise "lackluster" campaign, Politico

Meanwhile, Politico reports unnamed sources saying President Barack Obama is leaning more toward supporting Clinton as the more electable candidate — and one capable of keeping his policy legacy intact.

Two of Obama's top White House aides, John Podesta and Jennifer Palmieri, are running Clinton’s campaign and "report" regularly to former friends there, including the president, according to Politico.

Nevertheless, CNN has reported Obama has given Biden his "blessing" should he decide to run.