Indiana Democrats left the state for Illinois to prevent a vote on a bill that would allow workers to opt out of their unions and not pay dues. Taking a cue from Wisconsin, the legislators said they decided to cross state lines even though the Governor said that he would not send the police after them, and that he preferred the bill to be shelved. The Republicans say that they will allow the bill to die on the floor, but the Democrats want a promise that it will not be brought up again during this session.
See "Indiana Democrats Leave State to Avoid Union Vote", Susan Saulny and Sabrina Tavernise, The New York Times, February 22, 2011