The Justice Department has been busy combating public corruption. January saw the arrest of the former Speaker of the New York Assembly, Sheldon Silver, and his February indictment.

In March, headlines announced that federal corruption charges against New Jersey's senior U.S. Senator and current chairman of the Senate Foreign Relations Committee, Robert Menendez, were imminent. On April 1, Menendez was indicted. Generally, federal charges are politically toxic; it was a mere six days after his arrest that Silver was forced to relinquish his 21-year-hold on the Speakership. The very day that news first broke about Menendez, articles appeared speculating about his replacement. But politics are one thing, proofs another.

READ: Silver and Menendez: How Strong Are the Government's Cases?