Former President Barack Obama once urged an assistant, " Shoot Me. Now" about Joe Biden's frequent rambling, a new book shedding light on their supposedly strained relationship alleges.

The alleged hostility between the two stretches back to their time in the Senate, according to Gabriel Debenedetti, national correspondent for New York Magazine.

Book: Biden Rolled His Eyes Behind Obama

During their eight years in the White House, Obama and Biden were surrounded by articles about their alleged bromance. According to book excerpts, Obama's first impression of Biden was condescending, and he tended to ramble, evidently savoring every minute of it.

During George W. Bush's confirmation hearings for Condoleezza Rice as Secretary of State in 2005, Obama handed a letter to a staffer that said, 'Shoot. 'Now,' the text declares. Obama allegedly told close adviser David Axelrod, "Joe Biden is a great guy, but oh, that guy can just speak and talk. It's fantastic to witness."

The book also alleges that Biden rolled his eyes behind Obama's back at his aloofness and glad-handing with other pols" and was taken aback by his alleged "humorlessness." Barrack Obama, on the other hand, believed that Joe Biden's frequent gaffes in public would provide ammunition to their opponents.

Their relationship improved when Biden became Obama's right-hand man and they held weekly meetings together, as-stated-in book, according to NY Post. In early 2007, Biden strained his relationship with Obama further by calling him the first mainstream African American who is articulate, brilliant, clean, and a fine looking person" in an interview.

Biden's presidential campaign in 2008 was doomed from the outset, with even his biggest funders telling him that it "wasn't his time," that it belonged to Obama, who was also running. Relegated to the sidelines, Biden saw Hillary and Obama sparring with interest and serious displeasure.

Obama regarded Biden as a rival with an eye roll; and if he was scheduled to speak thereafter, he would inquire as to how much behind schedule they were. When it came to selecting his running partner, Barrack Obama was "pragmatic, not emotional," recognizing that Biden appealed to white people who were wary of Obama. Biden originally declined Obama's invitation, but his family persuaded him to reconsider.

Read Also: Graham Clarifies Prediction of 'Riot in the Streets' If Trump Is Indicted Over Classified Docs 

Biden Allegedly Defends Obama Despite Disagreement

Biden received assurances that the vice presidency would be a true collaboration and that he would be the last person in the room during critical discussions. But tensions arose almost immediately, and an atmosphere of mutual but still subterranean suspicion grew as Joe Biden was forced to defend Barack Obama's stances, even when he disagreed with them, as per Daily Mail.

According to the book, Obama picked Biden as his running mate for his 2008 presidential campaign out of pragmatism, but Biden first objected - as he described publicly. Obama eventually won Biden over by promising a complete collaboration with him that would serve as the capstone rather than the tombstone of Biden's career.

Early in Obama's presidency, Biden despised having to defend Obama's ideas with which he disagreed, but their relationship gradually improved. Still, there was some apprehension. Concerned about Biden's gaffes, Obama aides once barred him from accepting press questions or huddling with voters at rope lines, relegating him to a teleprompter, according to the book.

Their relationship looked to suffer yet another setback when Obama mulled replacing Biden as his running mate in 2012 with Hillary Clinton, according to the book. Previously, the Obama administration refuted the claim. Relations deteriorated further when Biden announced his support for homosexual marriage before Obama.

Biden was personally hurt during the 2016 campaign when Obama called Clinton his friend who would be a great president, tantamount to an endorsement in Biden's perspective. "Am I not required now?" Biden was said to have wondered at the time, Washington Examiner reported.

Related Article: Donald Trump Mar-a-Lago Raid: Unsealed Affidavit Reveals 'Top Secret' Files That Led to FBI Search 

@YouTube