WASHINGTON –Sen. Bob Menendez (D., N.J.) is expecting a federal indictment Wednesday, according to two New Jersey Democratic sources.

Menendez has been traveling, but is expected to be back in New Jersey tomorrow and people around him expect the long-awaited corruption charges to be brought then -- though there is some caution that there could yet be delays; previous predictions of imminent charges have proven premature. The case is being handled by the Department of Justice in Washington, but a grand jury has been meeting in Newark.

Politico reported the expected indictment Tuesday morning.

Menendez is expected to fight to clear his name. He is not up for re-election until 2018 and will almost certainly not resign his seat in the Senate, at least not quickly.

"He's going nowhere," said Mike Soliman, a former Menendez state director and close ally. "He will continue to fight for the people of New Jersey."

But his position as the top Democrat on the Foreign Relations committee could be in jeopardy just as nuclear negotiations with Iran – which Menendez has watched with a skeptical eye – reach a critical deadline.

Menendez's office did not respond to requests for comment Tuesday.

Menendez has been under investigation for his relationship with Salomon Melgen, a South Florida eye doctor and top campaign donor. Melgen, his family and employees have, over many years, given more than $1 million to Menendez and political committees that the Democrat either controlled or that were backing his re-election. He has also flown Menendez on his private plane and hosted him at a luxurious property in the Dominican Republic.

Three of the flights were not paid back or reported – as required by ethics rules – for years. Menendez in 2013 paid Melgen $58,500 for two flights years earlier, shortly before FBI agents raided the doctor's offices. He later had his campaign pay $11,250 for a third undisclosed flight, in 2011.

Menendez, meanwhile, pressed federal officials on two policy fronts in ways that could have helped Melgen's businesses. In one, he questioned the Medicare rules that resulted in Melgen being ordered to repay $8.9 million in payments from his Florida eye practice. In another, Menendez urged federal officials to take steps that would help another Melgen business win enforcement of a security screening contract in the Dominican. Both efforts have been revealed in news reports and a federal court filing that was mistakenly unsealed.

Menendez has repeatedly said he has always acted appropriately and that "every action" he has taken in the Senate has been to fight for the best policies for New Jersey and the United States. As word of the charges first surfaced earlier this month, he told reporters, "I'm not going anywhere."

Menendez has hired renowned attorney Abbe Lowell and has worked behind the scenes to build political support in New Jersey in advance of the charges. So far few in Washington have openly criticized him -- including Republicans, many of whom support his criticism of the Iran talks -- though one conservative group, American Commitment, has started a petition calling for him to resign.

Privately Menendez is said to have become emotional at times about the pending charges. He has long dreamed of being a senator and has broken barriers for Hispanics throughout his career. The son of Cuban immigrants, he grew up in a tenement before rising to his post in Washington.

A criminal charge with the potential to stain his legacy could come down this week.

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