One rider [to the bill] – Section 2262 -- de-funds certain White House adviser positions – or “czars.” The president in his signing statement declares that he will not abide by it.
“The President has well-established authority to supervise and oversee the executive branch, and to obtain advice in furtherance of this supervisory authority,” he wrote. “The President also has the prerogative to obtain advice that will assist him in carrying out his constitutional responsibilities, and do so not only from executive branch officials and employees outside the White House, but also from advisers within it. Legislative efforts that significantly impede the President's ability to exercise his supervisory and coordinating authorities or to obtain the views of the appropriate senior advisers violate the separation of powers by undermining the President's ability to exercise his constitutional responsibilities and take care that the laws be faithfully executed.”
Therefore, the president wrote, “the executive branch will construe section 2262 not to abrogate these Presidential prerogatives.”
In other words: we know what you wanted that provision to do, but we don’t think it’s constitutional, so we will interpret it differently than the way you meant it.