From the Washington Post editorial this morning, which is very tough on the White House on the Romanoff business, but also says it probably wasn’t a crime:

If this is not a quid pro quo — a federal job in exchange for dropping the Senate bid — it is uncomfortably close. Substitute Karl Rove for Jim Messina and imagine the uproar if the Bush administration had engaged in such a baldly political exchange.
Is it a crime? Probably not. Federal law prohibits anyone from promising federal employment as a “reward for any political activity,” but the Justice Department’s official guidance for prosecutors says this is “not intended to reach the consideration of political factors in the hiring or termination of the small category of senior public employees.”