WASHINGTON – It was business as usual for New Jersey Sen. Bob Menendez Monday – at least in public – just days after reports surfaced that he could face federal corruption charges in the coming weeks.

Menendez, the top Senate Democrat on foreign affairs, appeared as a speaker at an afternoon policy discussion on Russia at the Center for Strategic and International Studies, a foreign affairs think-tank situated near many foreign embassies. He was immediately followed by Zbigniew K. Brzezinski, the former national security advisor to President Carter.

A clutch of reporters awaited Menendez at the academic event, though the senator avoided those waiting at the front door, arriving through another route. He spoke without any acknowledgement of the questions swirling around him, instead focusing on pushing for a stronger U.S. response to Russia's aggression, including tougher sanctions, more military aide to Ukraine and a tougher military presence in the Balkans.

"Let Putin know that it's up to him how long we stay there," Menendez said.

He spoke for about 15 minutes and has a Senate vote scheduled later today.

So far, most fellow lawmakers are holding their fire in the wake of news of impending charges – aside from some Republicans who have come to his aid, wondering if the leak about the potential charges against Menendez comes because he has prominently bucked the Obama administration on Iran policy.

"The timing seems awfully coincidental," Sen. Ted Cruz (R., Tex.) told reporters in Iowa over the weekend. "It raises the suggestion to other Democrats that if you dare part from the Obama White House, that criminal prosecutions will be used potentially as a political weapon against you as well."

Sen. Lindsey Graham (R., S.C.), who has worked closely with Menendez on immigration reform and foreign policy, raised similar concerns to Bloomberg Politics Monday.

"It just doesn't smell right," he said, taking issue with Friday's leak of the expected indictment. "Reading in the paper that you're going to be indicted, that's not how the system works. I'm just disgusted with the whole process."

The National Republican Senatorial Committee, though, has called for Menendez to step down -- an outcome people who know him say is extremely unlikely, at least in the short term. Menendez said Friday, "I'm not going anywhere."

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