If both the President and the Vice President can no longer serve, who becomes President?

The Speaker of the House becomes President if both the President and Vice President are unable to serve. This line of succession is clearly outlined in the Presidential Succession Act of 1947, which establishes the order in which officials will assume the presidency in the event that the current officeholders are unable to fulfill their duties.

The Speaker is the highest-ranking member of the House of Representatives and is next in line after the Vice President. This position is significant because the Speaker is elected by the members of the House, making them a representative of the people's will, and they hold a constitutional role that ensures continuity in leadership.

The other positions mentioned, while important in government, do not have the same succession authority. The President Pro Tempore, typically a senior member of the Senate, is next in line after the Speaker and is not the immediate successor. The Secretary of State and the Chief Justice also do not have roles in the presidential line of succession as established by law. Thus, the Speaker of the House is clearly the correct choice.