Prosecutors rested their tax-evasion case against a Cook County commissioner Tuesday, giving his lawyers their chance to mount a defense, including by possibly calling the Chicago Democrat himself to the stand.

The federal judge presiding over William Beavers’ trial in Chicago said he expected the defense would start and finish their presentation Wednesday, with jurors hearing closing arguments later the same day.

Beavers, 75 and known his tough talk and bravado, has said for weeks he intended to testify. But his attorneys did not give a clear signal that he will, in fact, take the stand on Wednesday.

Beavers has denied diverting tens of thousands of dollars from his campaign coffers and spending it for personal use — primarily on casino slot machines — without reporting it as income on his 2006 through 2008 returns.

After prosecutors rested Tuesday, Judge James Zagel denied a defense motion to throw out the case on grounds the government sought to taint Beavers during their four-day case by emphasizing his gambling.

“I don’t think there was a theme, ‘Gambling is bad … and the defendant ought to be condemned,’” Zagel said.

Beavers is not on trial for using campaign money on gambling — which is not illegal — but, rather, for not reporting the campaign money he spent on gambling as income on his returns.

Prosecutors entered evidence that Beavers lost nearly $500,000 on slot machines — sometimes writing multiple, $2,000 checks from his campaign funds, then quickly losing the cash gambling. Their witnesses spent hours talking about how he cashed many campaign-fund checks within 30 minutes of apparent gambling binges.

But IRS agent Paul Ponzo, testifying for the government, conceded during cross-examination Tuesday that Beavers also withdrew tens of thousands dollars from his personal accounts. Defense attorney Aaron Goldstein asked Ponzo if he analyzed the proximity of personal withdrawals to times Beavers spent gambling.

“No,” said Ponzo.

“And so some or all of it (the withdrawals on Beavers’ personal accounts) could have been used on gambling,” Goldstein asked.

“It could have,” Ponzo answered.

Defense attorneys have argued that Beavers regarded much of the money from his campaign coffers as loans and that he eventually paid much of it back.

Beavers has pleaded not guilty to four federal tax-related counts. If convicted, he faces a maximum three-year prison sentence on each count.