It is surely unconstitutional to make a decision to prosecute party B on the basis of the fact that it is politically undesirable to prosecute party A but politically necessary to prosecute somebody.
That's what seems to have happened in Credit Suisse's case. The prosecutors decided to go after a relatively small foreign bank while allowing major U.S. banks and major U.S. tax evaders to go untouched. That is no way to protect the U.S. tax system.
Was Credit Suisse actually legally guilty of a crime? We will never know; the "guilty plea" is nothing but a business decision resulting from a highly asymmetric negotiation. Presumably there is some law under which a non-U.S. entity has a duty to protect the U.S. tax system; maybe the law is constitutional; maybe Credit Suisse violated it. In any case, it has agreed to say that it did so.
The Credit Suisse prosecution is a laughably transparent attempt to mask the Justice Department's complete refusal to prosecute powerful American individuals and institutions for their various crimes, ranging from tax crimes through securities and mortgage fraud and lying to Congress. Attorney General Holder is quoted as saying that "no financial institution, no matter its size or global reach, is above the law." That is obvious nonsense, and will be until U.S. individuals and institutions with actual U.S. clout are prosecuted.
That clout must include "revolving door" clout. Not only must it prosecute major U.S. financial institutions; if wants to regain any credibility, the Department of Justice must prosecute defendants that employ former high-ranking members of the government.
Of course, it would be very hard to prove how the Justice Department decided which institution to prosecute. In any case, in agreeing to plead "guilty" Credit Suisse has given up its opportunity to argue the question. To portray that as a victory for the rule of law is absurd.
