A federal jury convicted Chicago Democrat William Beavers of tax evasion.

A jury decided that Beavers, an old school Chicago ward boss who once dubbed himself “the hog with the big nuts,” was guilty of hiding money from the IRS in order to avoid paying income taxes.

Beavers was convicted on four counts for failing to report tens of thousands dollars from his campaign fund on federal tax returns between 2006 and 2008. He’s also charged with not reporting a nearly $69,000 campaign check he used to boost his city pension payouts – and $1,200 a month he received from his County Board account.

Earlier, the Cook County Commissioner’s federal tax-evasion trial took a colorful turn Thursday, when one defense attorney sprinkled his closing arguments with voice imitations, a reference to Lindsay Lohan and mocking jabs at the government’s star witness.

But Sam Adam Jr., the colorful defense lawyer who also represented ex-Illinois Gov. Rod Blagojevich, accused federal prosecutors of contorting the evidence against his client.

“They are trying to bamboozle you,” Adam told jurors, prompting Judge James Zagel to sternly warn him against making personal attacks during his closing argument.

Earlier, during the government’s closing statements, Assistant U.S. Attorney Carrie Hamilton said Beavers initially stopped reporting campaign money as income after getting hit with a big tax bill in 2005, a year when his tax returns reflected a $43,000 taxable campaign payout.

He started his scheme to avoid paying more taxes, Hamilton said.

“It was not a mistake. It was not inadvertent. It was intentional,” she said. “He knew that he had to claim that money and he did not.”

But it was Beavers’ penchant for playing the slots at the Horseshoe Casino in Hammond, Ind. – and his nearly $500,000 in gambling losses between 2006 and 2008 – that the government turned to in trying to establish a main motive for the alleged scheme.

Of the 100 campaign checks Beavers cut himself, 73 were cashed on the same day he was playing the slot machines, Hamilton said. She pointed to trial testimony showing that Beavers frequently wrote himself campaign checks, cashed them, and was then gambling just minutes later.

Beavers covered his tracks by retroactively noting on check stubs and other documents that the checks he wrote himself were for campaign expenses – even though some expenses were incurred months after the checks were cashed, Hamilton said.

She also pointed to testimony from the government’s star witness, IRS Agent Paul Ponzo, who said he couldn’t find a single scrap of paper to bolster Beavers’ claim that he simply loaned himself the money and always intended to pay it back.

But Adam spent much of his hour-plus closing statement ridiculing Ponzo. He also suggested the government shouldn’t rely on Ponzo’s analysis of Beavers’ tax documents – which he called a “Ponzo scheme” – because the agent once failed an accounting exam.

“That’s like Lindsay Lohan telling Betty Ford how to tell people how to get off drugs,” he said. “That’s like Lovie Smith telling Phil Jackson how to win championships.”

At the heart of Adam’s lively closing statement was his contention that Beavers’ intent – whether he meant to repay the money he withdrew – was the only thing that should matter to jurors. Adam pointed to evidence that Beavers eventually paid back nearly 87 percent of the money he withdrew, even if there were no loan documents.

Judge Zagel had previously ruled no one can speak to Beavers’ intent but the commissioner himself, who announced Wednesday he would not testify, after months of promising he would.

Earlier, Adam for the first time acknowledged his client “may have a gambling problem,” but suggested Beavers used his own personal cash for gambling, not campaign money.