Final enactment typically requires approval from the head of state or executive authority. In parliamentary systems, this may be largely ceremonial, while in presidential systems like the United States, the executive may exercise veto power. The Affordable Care Act (ACA) exemplifies this complex process, having undergone extensive committee hearings, multiple amendments, heated floor debates, reconciliation between House and Senate versions, and ultimately presidential signature in March 2010, transforming a campaign promise into comprehensive healthcare legislation affecting millions of Americans.