I would go for removing those four words from the preamble immediately and then remove from the playing field every department, administration agency, etc that does not comport with those powers granted, specifically.
It would be sufficient merely to recognize that if a parent instructs a child to do X in order to do Y, that confers neither a general permission to do X, nor a general purpose to do Y, but only to do X insofar as is necessary to do Y, and only to do Y to the extent possible by doing X together with other expressly-authorized actions.
If a parent instructs a child to go to the store and buy some table decorations so the dining room will look nice for upcoming guests, that is not an instruction to go out to the store and buy anything the child sees fit, nor is it an instruction to do anything and everything that might help the dining room look nice for the upcoming guests. A child who claimed that he was told to buy a new XBox game, or to destroy his sister's toys which were sitting on the table, would likely be soundly scolded.
If parents can recognize that such behavior is inappropriate in a child, is there any reason the public shouldn't recognize that such behavior is in appropriate in a government?