An anonymous congressman has dropped a bombshell election-year book that confirms why Americans hate their national government and have rallied to anti-establishment presidential candidates like Donald Trump.

The veteran politician lays bare a rotten and corrupt Congress enslaved by lobbyists and interested only in re-election in an anonymous, 65-page manifesto called “The Confessions of Congressman X.”

“Like most of my colleagues, I promise my constituents a lot of stuff I can never deliver,” he admits. “But what the hell? It makes them happy hearing it . . . My main job is to keep my job.”

The House member — a Democrat who is either still in Congress or served sometime over the past two decades — says more time is spent fundraising than reading bills and calls Washington a “sinkhole of leeches.”

The title of one chapter sums up his view of congressional leaders: “Harry Reid’s a Pompous Ass,” he says of the Senate Democratic leader.

The book, published by the small Mill City Press, is based on years of transcribed private discussions, which the congressman last November gave editor Robert Atkinson.

Atkinson declined to say whether Congressman X is a current or former House member.

X says the cloak of anonymity gave him the freedom to expose ­secrets, including how the public’s money is wasted.

“We spend money we don’t have and blithely mortgage the future with a wink and a nod. Screw the next generation. It’s about getting credit now, lookin’ good for the upcoming election,” he says.

He said he and his colleagues often lie to try to be all things to all people instead of tackling the nation’s problems.

“I contradict myself all the time, but few people notice,” X says. “One minute I rail against excessive spending and ballooning debt. The next minute I’m demanding more spending on education, health care, unemployment benefits, conservation projects, yadda, yadda, yadda.”

Voters are described as gullible, know-nothing jerks, while the only people who count are the big donors who pour billions of dollars into lobbying.

“Voters are incredibly ignorant. It’s far easier than you think to manipulate a nation of naive, self-absorbed sheep who crave instant gratification . . .,” vents Congressman X.

He says money “corrupts” and House members are “puppets” to lobbyists who bankroll their campaigns.

‘America’s on an irreversible decline and no one in Washington seems to care . . . God help us.’ - Congressman X

“Business organizations and unions fork over more than $3 billion a year to those who lobby the federal government. Does that tell you something? We’re operating a f–king casino,” he says.

He describes himself as a “closet moderate” who supports charter schools and tax vouchers to allow poor kids to go to private schools.

But students take a back seat to partisan politics..

“Our education’s in the toilet, and all we do is snipe at each other,” he says.

Congress is too polarized and partisan to get anything done, by the congressman’s account.

“There seems to be a complete disintegration of confidence in government. A fear that government is its own special interest,” he says.

“America’s on an irreversible decline and no one in Washington seems to care . . . God help us.”

The controversial book set off a guessing game in the political world about the author’s identity.

New York sources speculated it’s Rep. Steve Israel (D-LI), a moderate who announced he’s retiring and who has complained about the constant need to fundraise to finance re-election campaigns.

But Israel, a novelist, denied that he took pen to paper this time.

“Absolutely not true, never heard of it before. And frankly, now that I’m leaving Congress, if I were to write a book like that, I would put my name on it,” ­Israel said in a statement.