Sen. Robert Menendez (D-N.J.) arrives at federal court in Newark on Monday for his corruption trial. The jury began deliberating at the end of the day whether Menendez misused his office to help a friend and donor with business and personal interests. (Jeenah Moon/Bloomberg)

A federal jury in Newark began deliberating Monday on whether Sen. Robert Menendez (D-N.J.) misused his office to help a friend and donor with business and personal interests.

In his closing argument on Monday, Menendez attorney Abbe Lowell said his client's "deep and abiding friendship" with co-defendant Salomon Melgen, a Florida eye doctor, "destroys every single one of the charges" against them.

Over the course of nine weeks, jurors have heard evidence about private jet flights, a luxury hotel stay and other gifts prosecutors say add up to a corrupt bargain between the two men. Defense lawyers have argued the relationship between them was based on a close personal friendship, not influence-peddling.

"Not one document, not one email hints at a corrupt agreement," Lowell told the jury during his three-hour presentation. "You should expect and demand more from the government when they have the burden to prove a case beyond a reasonable doubt."

Prosecutor Peter Koski argued in his rebuttal that defense attorneys have used "sleight of hand" to get the jury to shift focus away from "a greedy doctor and a corrupt politician."

[Indictment of Sen. Robert Menendez and Salomon Melgen]

Menendez allegedly accepted a Paris hotel stay, political donations and trips on Melgen's private plane in exchange for helping Melgen get U.S. visas for his girlfriends, intervening in the doctor's $8.9 million billing dispute with Medicare and trying to preserve Melgen's port interests in the Dominican Republic.

Lowell, who choked back tears at the end of his closing argument, said Menendez has dedicated his life to public service and to helping any person in need. He argued that Menendez's advocacy for Melgen either involved a routine matter such as acquiring tourist visas or reflected broader policy concerns such as port security or government waste.

Lowell attacked the prosecution's theory that Menendez and Melgen's longtime friendship grew into a criminal conspiracy after Menendez entered the Senate in 2006.

[Supreme Court makes it hard to prosecute corruption]

Koski said Menendez's advocacy for Melgen went far beyond the normal course of an elected official's work and that Menendez "exploited his public office for personal benefits."

"This is not how United States senators behave," Koski told the jury. "Don't let it stand. Don't let this stand. Hold Senator Menendez and Dr. Melgen accountable for their actions."

Koski said Monday that Melgen paid Menendez to be "his personal United States senator," a line prosecutors used during opening statements and in the first round of closing arguments last week.

Lowell said Menendez committed an unintentional oversight when he didn't list some gifts from Melgen on Senate disclosure forms. A false statement charge is one of the 18 counts in the indictment against Menendez.

"Bob is an honest and trustworthy man and not a corrupt person," Lowell told the jury.

The defense argued Monday that Menendez paid for some of his flights to Melgen's home in the Dominican Republic, where he enjoyed quiet family visits, not luxurious Caribbean vacations. The gifts between the men flowed both ways and were purely out of friendship, Lowell said, pointing to a $1,000 cash gift that Menendez gave when Melgen's daughter got married in 2009.

The trial has taken place against the backdrop of last year's Supreme Court ruling that overturned the corruption conviction of former Virginia governor Robert F. McDonnell (R).

U.S. District Judge William Walls tailored his jury instructions last week to conform to his reading of the McDonnell ruling, which narrowed the definition of an "official act" by a politician.

Walls denied a defense request Monday to require the jury on guilty verdicts to specify the "official acts" Menendez performed in return for bribes.

The jury deliberated for about an hour Monday before going home and will continue from about 9:30 a.m. until 4:30 p.m. most days until it reaches a verdict.

If no verdict is reached by Friday, Walls said he will excuse a female juror who said during jury selection that she had a vacation planned for mid-November. That juror will be replaced by an alternate, with deliberations starting over.