Adding another wild-card to the 2012 campaign’s final days, a former aide to Vice President Joe Biden has written a tell-all Washington memoir in which he lacerates the former Delaware senator as an “egomaniacal autocrat” who was “determined to manage his staff through fear.”

The book is hardly an objective study of the vice president, however. Author Jeff Connaughton, a Biden Senate staffer turned lobbyist, is by his own admission deeply disillusioned with the capital and embittered about his experience with the man who inspired him to enter politics.

Connaughton wrote “The Payoff,” which came out last month, in the fashion of guilt-racked whistle-blower: he was a party to a corrupt system and now wants to blow the lid off the game.

“I came to D.C. a Democrat and left a plutocrat,” he confesses.

As chief of staff to former Sen. Ted Kaufman (D-Del.), Biden’s successor, Connaughton was radicalized by his unsuccessful experience trying to get an amendment to the Dodd-Frank financial regulation bill that would have broken up the country’s largest banks. So he left Washington politics and wrote what he believes is the unvarnished truth about the country’s political system. The big reveal: Big banks control both parties.

“It’s time people understand why – and how – Wall Street always wins,” Connaughton writes at the outset of his book.

He is harshly critical of his own party and the Obama administration, arguing that the president is no different than most other Washington Democrats in his willingness to kowtow to Wall Street.

President Obama and Biden, he writes, are “both financially illiterate.”

“The Payoff” is every bit the cri de coeur of a man who, as he writes, is “willing to burn every bridge” in order to indict the transactional Washington lobbying and political culture. (After Kaufman’s term ended, Connaughton fled D.C. and moved to Savannah, Ga.)

But the book is also a reprise of the familiar cautionary tale about an idealistic young politico who came to Washington to make a difference but went native – and was let down by the powerful man he looked up to.

Time and again, over the course of decades, Connaughton tells of being disappointed in Biden or not receiving the treatment he felt he was due. He doesn’t hide his sour grapes - he’s up front about his unhappiness and that he never gained the full trust of the former Delaware senator.

“Only a handful of people ever made it into his inner circle,” he writes, adding: “I simply wasn’t one of the chosen.”

What’s remarkable about the book is the lengths that Connaughton goes to portray his former boss and political idol in a bad light, piling up embarrassing anecdotes and examples of when Biden couldn’t be bothered to help one of his own aides.