Presidential Succession: Article 2, Section 1, Clause 6, Constitution of the United States: In Case of the Removal of the President from Office, or of his Death, Resignation, or Inability to discharge the Powers and Duties of the said Office, the Same shall devolve on the Vice President, and the Congress may by Law provide for the Case of Removal, Death, Resignation or Inability, both of the President and Vice President declaring what Officer shall then act as President, and such Officer shall act accordingly, until the Disability be removed, or a President shall be elected.

If the president is no longer able to serve, the vice president would serve as president.

If the vice president is unable serve, the line of succession falls to the speaker of the House, then to the Senate president pro tempore, then to Cabinet members.

The Cabinet line of succession is:

1. Secretary of State

2. Secretary of the Treasury

3. Secretary of Defense

4. Attorney General

5. Secretary of the Interior

6. Secretary of Agriculture

7. Secretary of Commerce

8. Secretary of Labor

9. Secretary of Health and Human Services

10. Secretary of Housing and Urban Development

11. Secretary of Transportation

12. Secretary of Energy

13. Secretary of Education

14. Secretary of Veterans Affairs

15. Secretary of Homeland Security

The 25th Amendment allows the vice president to serve as acting president temporarily in the case that the president is ill or otherwise temporarily unable to fulfill his or her official duties.