As of 2016, the current Constitutional succession order currently following the death of the President is: 1 Vice President 2 Speaker of the House 3 President Pro Tempore of the Senate 4 Secretary of State 5 Secretary of the Treasury 6 Secretary of Defense 7 Attorney General 8 Secretary of the Interior 9 Secretary of Agriculture 10 Secretary of Commerce 11 Secretary of Labor 12 Secretary of Health and Human Services 13 Secretary of Housing and Urban Development 14 Secretary of Transportation 15 Secretary of Energy 16 Secretary of Education 17 Secretary of Veterans Affairs 18 Secretary of Homeland Security The order is based on when each Department became a Cabinet-level post.
According to the time on the television on which Tom Kirkman is viewing the State of the Union address (10:15 p.m. Eastern) and the time shown in the Presidential Emergency Operations Center (10:39 p.m.), Kirkman was moved to the White House and sworn in as President in fewer than 25 minutes.
When the Federal Judge is swearing in the new President she correctly reads the oath of office, which does not include the phrase 'so help me God', Kirkman then chooses to add the phrase himself. By contrast the real Chief Justice has incorrectly added the words during the last two US Presidential inaugurations.
During the State of the Union Address, or any time when Congress and the President are meeting in one place, there is not one but three "designated survivors." One from the Cabinet, one from Congress, and one from the military. They are kept in a secured secret location outside of Washington, DC, in another place in the United States.
In the bathroom scene, Seth is speaking to Kirkman in the next stall without knowing it's him. Seth exclaims "I have half a mind to make a run to Canada." The double in-joke is that they are already in Canada since the show was filmed in Toronto and that Kiefer Sutherland is a Canadian actor. The intended irony seems to be emphasized with Seth steps out and is shocked to see Kirkman, and Kirkman whimsically repeats to Seth, "Canada?" with a stereotypical Canadian accent.