NEWARK -- U.S. Sen. Robert Menendez listened intently at the defense table as a federal prosecutor spelled out for the jury why they were all there.

"This case is about a corrupt politician who sold his Senate office for a life of luxury he couldn't afford," said Peter Koski, deputy chief of the Justice Department's Public Integrity Section, as he opened the government's case against the New Jersey Democrat charged in a sweeping scandal alleging bribery and corruption to help a wealthy benefactor.

More than two years after Menendez was indicted of accepting flights on private jets, trips to Paris and other lavish personal gifts from Dr. Salomon Melgen -- in exchange for using the power of his office to help the Florida opthmalmogist in Washington -- the courtroom drama that could have far-reaching political ramifications began in Newark, with openings by the prosecution and the senator's defense team.

The government has alleged the senator, a Cuban immigrant's son who became a fixture of the Hudson County political scene, ran interference for Melgen in government matters ranging from the visa applications of the doctor's three girlfriends to his attempts to secure a port security contract in the Dominican Republic.

In exchange, Melgen is accused of lavishing the senator with more than a dozen private plane flights, stays at a Paris hotel and a resort in the Dominican Republic, and more than $750,000 in political contributions.

The 63-year-old lawmaker now faces what's expected to be a six- to eight-week trial before U.S. District Judge William H. Walls that could further upend Capitol Hill, and will largely focus on one question: What's the difference between a bribe and a gift between friends?

In addition to the visa applications and port security negotiations, prosecutors allege Menendez also intervened in the doctor's $8.9 million Medicare billing dispute with the Department of Health and Human Services, going as far as enlisting then-Senate Majority Leader Harry Reid's help in lobbying Kathleen Sebelius, the HHS secretary at the time.

Menendez's fellow senator from New Jersey, Corey Booker, attended the trial and claimed a seat in the gallery for defense attorney Abbe D. Lowell's opening statement.

The lead attorney on Menendez's defense team, Lowell -- a veteran white-collar litigator who has represented everyone from John Edwards to Jack Abramoff -- argued the men's friendship cut through the prosecution's premise.

"That premise is that Sen. Bob Menendez did everything they accuse him of doing because he had a corrupt relationship with Dr. Melgen," he said. But in writing the indictment, which covers a period between 2006 and 2012, prosecutors left out a previous 14 years of friendship between the two men, Lowell said.

While Koski, deputy chief of the Justice Department's Public Integrity Section, framed the men's relationship as a regular swapping of money for power, Lowell and Kirk Ogrosky -- opening for Melgen's defense -- argued there was not "one single piece of evidence" supporting any quid pro quo arrangement.

Instead, Lowell argued, the issues at stake in Menendez's interactions with other officials in the case went far beyond Melgen's concerns. The defense attorney said the Senator's involvement in the visa applications stemmed from his concerns about the women's "fair treatment" by immigration authorities, while his intervention in the Dominican Republic port screening contract stemmed from his concerns about security issues in the island nation.

"This case isn't really about what happened," Lowell said. "It's about why it happened."

A grand jury in New Jersey first handed down charges against the two men in a 22-count indictment filed on April 1, 2015. Prosecutors this October filed a new 18-count "superseding" indictment amending the problematic legal language in the bribery accusations.

Melgen, 63, is already in federal custody, having been convicted at trial in January of a $90 million Medicare fraud scheme following an FBI investigation of the disputed billing practices. During Koski's opening remarks, he sat slumped in his chair with his chin on his chest, his eyes barely raised to look at the prosecutor.

In the New Jersey case, both men are charged with conspiracy, bribery, honest services fraud, violating the federal Travel Act, which outlaws travel for criminal purposes. Menendez is also charged with making false statements on government disclosure forms by failing to report the numerous plane flights and hotel stays he was gifted by Melgen.

"These defendants didn't just trade money for power -- they also tried to cover it up," Koski said, referring to the undisclosed gifts. But Lowell, speaking to Menendez's intent, told the jury that "the rules of what goes on and off these forms are confusing," and that many of the gifts would not normally have to be disclosed under ethics codes which changed during the timeframe specified in the indictment.

In arguments Wednesday morning prior to opening statements, defense attorney Raymond M. Brown, a member of Menendez's team, told the judge he felt the defense had been disparaged by one of Walls' opinions that speculated on their motives.

In his Aug. 31 opinion denying the motion to adjourn, Walls wrote he suspected the defense strategy behind the motion, "if granted, would be to impress the jurors with the public importance of the defendant Senator and his duties."

In court, Walls denied having disparaged the defense, and said he did not think there was a lack of respect in his lawyer-to-lawyer criticisms of the attorneys.

Menendez is only the second sitting U.S. senator to stand trial in the past decade. Ted Stevens, a Republican from Alaska, was convicted at trial in 2008 of failing to report more than $250,000 in gifts from an oil company. A judge later threw out the conviction.

Ogrosky is expected to conclude his opening remarks Thursday morning.

Thomas Moriarty may be reached by email at tmoriarty@njadvancemedia.com. For confidential tips, you can make an anonymous ProtonMail account to send him encrypted messages at tmoriarty@protonmail.com. Follow him on Twitter at @ThomasDMoriarty.

MaryAnn Spoto may be reached by email at mspoto@njadvancemedia.com. Follow her on Twitter @MaryAnnSpoto.

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