Amid the continuing investigations into Russian meddling in the 2016 presidential election, there, of course, has been a great deal of discussion and news coverage of the 45th commander in chief not completing his full term in office.
If a sitting president leaves office, the vice president — currently Mike Pence — becomes the POTUS for the rest of the term. If the VP is unable to serve, the next person in the line of succession acts as president (see the chart below). To date, only a VP has ever replaced the president.
The second in line, after Vice President Pence, is Paul Ryan, the speaker of the House of Representatives. And that oilman, who’d follow Ryan and then President pro tempore of the Senate Orrin Hatch, into the West Wing? That would be Secretary of State Rex Tillerson.
American presidential succession laws first date to 1792. The line of succession has been shuffled several times since: for example, in 1868, when Congress removed the leaders of the Senate and House of Representatives from the list, and, most recently, in 1967.