Final answer:
In a U.S. presidential election, winning all states except one is not sufficient to obtain the necessary 270 electoral votes to win the presidency.
Step-by-step explanation:
In a presidential election in the United States, a candidate needs to gather at least 270 electoral votes to win the presidency. The Electoral College system determines the winner based on these votes. So, if a candidate wins all states except one, they will fall short of the necessary 270 votes and will not win the presidency.
Learn more about U.S. presidential election