FORT LAUDERDALE, Fla. — Federal law enforcement is outlining its case against Sen. Robert Menendez, alleging they have the evidence to show a pattern of corruption that includes a $20,000 flight to the local airport here.

When the private plane of a South Florida eye doctor who has been a friend and supporter of Menendez was unavailable to transport the New Jersey Democrat and others from the Dominican Republic, Dr. Salomon Melgen procured a friend’s plane.

At least that’s the allegation of federal prosecutors in Newark, N.J., outlining the case in a Wednesday court filing. Arguments are slated to begin in one week on Sept. 6, and elements of the federal trial could put the Senate’s internal operations under fire, as well.

Menendez was allegedly a frequent guest of Melgen’s in the Dominican Republic. The opthamologist has already been convicted in South Florida of substantial Medicare fraud.

“At trial, the jury will hear about Menendez’s luxurious Dominican travel through witness testimony from those who were there, and they will see Melgen’s resources placed at Menendez’s disposal for these trips in, among other things, contemporaneous emails, resort records, flight records, and credit card and bank statements,” government lawyers told the New Jersey court Wednesday.

The government is preparing to argue that the size of scope of the gifts to Menendez in the Dominican Republic and elsewhere is in fact relevant to establishing motivation, with the defense indicating that Melgen was being driven to give generously as a result of a friendship.

“Although Menendez did not pay Melgen back for the lavish gifts in money, he did pay him back using the currency of his Senate office to take official action to benefit the South Florida doctor,” the federal prosecutors said. “Email exchanges between the defendants, their agents, and officials from Executive Branch agencies will show Menendez’s considerable efforts to pressure the Executive Branch on Melgen’s behalf. And testimony from the agency officials over whom he exerted that pressure will illuminate the relentlessness of those efforts.”

Among those witnesses from federal departments and agencies may be those from the Centers for Medicare and Medicaid Services, given Melgen’s large billing disputes over the treatment of Medicare patients (and as the federal court in Florida found, actual fraud), as well as those involved in granting visas so that girlfriends of Melgen could lawfully enter the United States.

Beyond outlining the basis of the federal case against Menendez, the filing shows some of the government’s rebuttal to potential defenses from the senator’s legal team. Of particular interest may be the fact that “the Government does not intend to offer any evidence of legislative acts taken by Menendez.”

That’s because of previous legal wrangling that has defined how the Constitution’s Speech or Debate clause insulates Menendez from certain charges of impropriety, as would be the case with any member of Congress.

“The Government notes, however, that Menendez may offer such evidence,” the federal prosecutors note, however, previewing a potential opening. “Should he do so, thus putting his legislative acts in issue, the Government is entitled to counter it with evidence of otherwise-protected legislative acts.”

The Justice Department’s lawyers also anticipate an attempt to argue that omissions from the Senate’s financial disclosures regarding things of value received by Menendez from Melgen are governed by the Senate Ethics Committee.

In Wednesday’s filing, the lawyers for the government are dismissive of the idea that Senate Rule 34, which allows that “gifts of any kind based on personal friendship may be accepted” is irrelevant to enforcement of federal laws against public corruption. That may set up a separation of powers conflict in court that could further complicate the proceedings. 

“Under those statutes, it is Melgen’s offering and Menendez’s acceptance of gifts intending to influence the latter in his official acts that determines their culpability,” the lawyers wrote. “How the Senate decides to police its own members has nothing to do with whether the defendants committed the charged offenses … Moreover, the Senate has no authority to overwrite or change the application of federal statutes by promulgating its own internal, administrative rules.”