Groucho Marx once said he didn't want to belong to any club that would accept him as a member.

Somewhere, Sen. Bob Menendez is nodding his head. That's because this past week the New Jersey Democrat joined a club no politician wants to be in: He became one of only 12 U.S. senators to be charged with a crime while serving in the world's greatest deliberative body.

At issue is Menendez's relationship with Salomon Melgen, a wealthy Florida eye doctor. The Justice Department alleges - in a 14-count indictment that came down Wednesday - that the lawmaker intervened repeatedly on Melgen's behalf in exchange for hundreds of thousands of dollars in campaign contributions to Menendez and other interests tied to him. That intervention included wading into a port dispute in the Dominican Republic and helping to obtain visas to the United States for three of Melgen's girlfriends.

Menendez insists that there was absolutely no quid pro quo at work in his relationship with Melgen. "I'm angry and ready to fight," the senator said at a news conference Wednesday night responding to the corruption charges.

That's a good thing, since the case against him is daunting - a 68-page charging document provides granular detail on just what the senator allegedly received from Salomon. It says the gifts included 19 free rides on private jets for Menendez and guests, long weekends to visit Melgen in Florida and the Dominican Republic, and, oh yeah, a $600,000 super PAC donation earmarked to help to reelect Menendez in 2012.

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In court, Menendez is innocent until proven guilty. But in politics, there's no such thing as a presumption of innocence, and the news - which broke on April Fools' Day - is nothing short of a total disaster for him.

Bob Menendez, for your new membership in the Senate's least-distinguished club, you had the worst week in Washington. Congrats, or something.

Cillizza covers the White House for The Washington Post and writes The Fix, its politics blog.