NEW YORK — Defense attorneys spent all day Tuesday working to undermine one of federal prosecutors’ star witnesses in their corruption case again Sen. Bob Menendez.

The witness, Jose Uribe, a New Jersey trucking and insurance industry figure who pleaded guilty earlier this year to bribing the senator and his wife, was repeatedly asked about his criminal record, which includes a history of fraud and lying to authorities. Uribe testified in vivid detail on Monday about a series of meetings with the senator, including a backyard gathering where they shared brandy.

Uribe has said he bought the New Jersey Democrat’s now-wife, Nadine, a new Mercedes-Benz in 2019 to gain the senator’s power and influence. Uribe wanted Menendez to disrupt a New Jersey state prosecution and investigation circling Uribe’s insurance business. The government has charged two other businesspeople with bribing the senator, but the car-related bribery charges may rest largely on how jurors view Uribe’s testimony.

What a jury will make of his credibility, of course, remains to be seen. But Uribe remained calm and at times exceedingly precise in his answers during cross-examination Tuesday, even as he admitted to a troubled past full of wrongdoing.

When Uribe was called to the stand and questioned by federal prosecutors on Friday and Monday, they tried to inoculate him from some of the coming attacks by asking their own questions about a series of crimes he has pleaded guilty to, including some unrelated to his interactions with the Menendezes.

Adam Fee, an attorney for Menendez, tried to drive home what those crimes were, at times using questions that were stricken from the record by the judge — though obviously said in front of jurors.

“You’re a very good liar, aren’t you?” Fee asked at one point, while going through a litany of wrongdoing Uribe has admitted to.

Those activities include submitting false documents to get a bank loan; using figures from those false documents to get a separate pandemic-era loan from the federal Small Business Administration; failing to file taxes; lying on his taxes; and providing dud insurance policies to trucking companies.

Fee pointed out that Uribe operated an insurance business in New Jersey for over a decade even though Uribe had lost his state insurance license in 2011. Even though Uribe actually ran it, on paper it was registered to a friend of Uribe’s daughter who, according to Fee’s questions, had come to Uribe for help when she was a pregnant teenager.

Because Uribe was not allowed to operate the business, he agreed with Fee that this arrangement meant Uribe had broken the law “every day” from 2011 until Uribe agreed to cooperate with Menendez’s prosecutors earlier this year and stepped down from the company.

Fee worked to distance Uribe from his client, the senator. Though Uribe testified earlier about a series of meetings with the senator, Uribe never had any written communication with Menendez. Unless Menendez testifies in the trial, that means Uribe’s account is the only one likely to be available to jurors about face-to-face meetings the senator had with Uribe, as well as a phone call.

Fee also asked questions that tried to highlight Uribe’s interactions with the senator’s wife, Nadine Menendez. Fee, for instance, asked Uribe if he knew Nadine would be helping Uribe in “manipulating” or trying to “deceive” the senator.

Elements of this strategy, known colloquially among trial watchers as the throw-her-under-the-bus defense, was used by the senator’s legal team in opening arguments and suggested in other questions Menendez’s attorneys have asked during the trial, which began last month and is expected to run through the end of this month.

Fee also asked repeated questions trying to establish that Uribe wanted the senator to think of him as a legitimate businessperson. The purpose of these questions, it seems, were to suggest that Menendez was deceived by Uribe.

At times, Uribe would correct Fee and an attorney for Menendez co-defendant Wael “Will” Hana about Uribe’s own previous testimony. Hana is also accused of bribing the Menendezes.

At other times, Uribe did not recall things that, had he said them in front of jurors, might have damaged him further — like the specifics of the 2011 case that cost him his insurance license or whether he issued a dud insurance policies to specific people, including Hana, that ended up hurting their businesses.

But Uribe also did not recall interactions that, had they occurred, would have presumably hurt the senator’s case. Uribe said, for instance, that he and Menendez never discussed the car he bought for Nadine “at all.”

Fee and Hana’s attorney who questioned Uribe, Ricardo Solano Jr., also probed the fact that Uribe has a lot on the line. For the crimes he’s pleaded guilty to, Uribe faces up to 95 years in prison. Uribe said he’s hoping for a more lenient sentence or to avoid jail time following his cooperation with the government.

During cross-examination, Uribe was also questioned about whether he was trying to cooperate with the government to spare his family, which was involved in his businesses, at least on paper, and could presumably be investigated or prosecuted too.

“I had lied in the past to protect my family, yes,” Uribe said.

Defense attorneys had hoped to use even more of Uribe’s past against him. But, without jurors present, the judge denied moves to introduce evidence or ask about Uribe’s failure to pay child support for what was described as a “limited period of time” or about a matter referred to by the judge as “the strip clubs.”

Those two lines of cross-examination could have undermined things Uribe said about his family values. He said he bribed the Menendezes to protect his family or close friends and talked about how he set aside Sundays for church, visiting his mother’s grave and his father in a nursing home and having family dinners.

An attorney for Hana, Larry Lustberg, said Uribe had been “left in tatters” after the cross-examination, and he doesn’t think Uribe’s testimony established guilt beyond a reasonable doubt — the standard jurors must use when they evaluate the defendants.

“The testimony speaks for itself,” Bob Menendez said leaving the courtroom.