WASHINGTON - Sen. Bob Menendez (D., N.J.) took his fight against federal corruption charges to the Supreme Court on Monday, petitioning it to hear his arguments that key evidence and charges should be dismissed.

Menendez has long argued that prosecutors overstepped rules meant to protect the legislative branch from executive branch intimidation.

He is hoping to persuade the court to throw out many of the charges and critical evidence against him, citing the Constitution's speech or debate clause, which shields legislative activity from prosecution.

Menendez has been accused of using his office to go to bat for a close friend and major campaign donor, Salomon Melgen, a South Florida ophthalmologist, in exchange for lavish gifts, including more than $1 million in campaign donations and luxurious vacations.

"This court's intervention is needed to restore the vital role the clause was designed to play in securing the separation of powers," Menendez's lawyers wrote.

Menendez's arguments have been mostly rejected in U.S. District Court and by the Court of Appeals for the Third Circuit, but his attorneys wrote that those rulings conflict with decisions in other circuits and must be resolved by the Supreme Court.

"A member's immunity cannot turn on which state he represents, or where the executive chooses to ask its questions," the petition says.

It is up to the Supreme Court justices to decide whether to hear the case. They have wide latitude over which of the many petitions they will formally hear.

The appeal to the high court comes six months after the justices unanimously threw out the corruption conviction of former Virginia Gov. Bob McDonnell, a ruling in which the court criticized prosecutors for using an overly broad definition of bribery.

Menendez's lawyers cite that case in arguing that the senator's aid for Melgen was the kind of activity that public officials do routinely for constituents seeking help, not criminal action.

Prosecutors charge that in exchange for Melgen's generosity, Menendez pressed federal officials on the doctor's business and personal interests.

He argued on Melgen's behalf as the doctor faced questions about allegedly overbilling Medicare by $9 million, and in a fight over a lucrative port security contract in the Dominican Republic. Menendez's office also tried to help Melgen secure visas for his foreign girlfriends, the government alleges.

Menendez's lawyers contend that the meetings he took and arguments he made were the actions of a senator digging into policy questions and performing legislative oversight.

Those activities, they argue, fall under the speech or debate clause. They say the gifts from Melgen were presents between friends.

Prosecutors say Menendez's work went beyond typical legislative activity, and crossed over into bribery.

If his appeal prevails, they have argued in earlier filings, Menendez would effectively create a class of super-citizens immune from prosecution.

The government will have a chance to respond to Menendez's petition, but declined to comment on his latest filing.

The Third Circuit rejected Menendez's arguments this year, but allowed him to seek a hearing at the Supreme Court. The senator's trial is not scheduled to begin until fall 2017.

Under separate circumstances, former U.S. Rep. Chaka Fattah (D., Pa.) also unsuccessfully cited the speech or debate clause in his recent corruption trial. He was sentenced to 10 years in prison this week.