The acting President has all Presidential power and duties during the time of his or her term . Under both the 25th Amendment and the Presidential Succession Act , an Acting President has identical constitutional `` powers and duties '' as the President , being able to sign bills into law , petition Congress for a declaration of war , and perform other tasks , but does not hold the office of President itself . The incapacitated President remains the sole holder of the presidential office , although the powers and duties of the presidency are transferred to the Acting President .