The President has recently announced he is delaying implementation of the employer mandate portion of the Affordable Care Act (ACA), more commonly known as Obamacare. The law, however, states that it is to go into effect in 2014, not later.
Article II, Section 3, of the Constitution states that the president "shall take Care that the Laws be faithfully executed." This would seem to state that the President MUST execute the law as written. The petition signers are confused as to what authority gives the President the right to choose not to enforce particular laws.
So the petition signers request that the President explain himself, and detail under what authority he believes he can defer the implementation of a law given Article II Section 3 of the constitution.