I’m going to explore a plausible, although unlikely, way the 2020 Presidential election could unfold by answering the question: Could Mike Pence cast the deciding vote to make himself the next President? Here’s how this could play out:

Neither Trump nor Biden captures a majority of votes in the Electoral College. There are several ways this could happen, but the most likely is a tie at 269 each. Other possibilities include a third party candidate winning one or more states (unlikely at this point), faithless electors preventing a majority (also unlikely), or contested results in one or more state preventing certification of their electors (despite rhetoric to the contrary, this too is unlikely). While there are many ways a tie could occur, here is what I think is the most likely scenario. Start with the current realclearpolitics.com electoral map, which shows 232 electoral college votes for Biden and 125 for Trump with 12 states and 2 congressional districts (one each in Maine and Nebraska) as tossups. If we assume Biden picks up the states Clinton won in 2016 plus Wisconsin and Arizona and Trump holds the rest of the states he won in 2016, the result is a 269-269 tie. Not sure I’d call this outcome likely, but it is definitely possible. 

The election goes to the House for President and the Senate for Vice President. If no candidate receives a majority of Electoral College votes, the 12th Amendment states that the House will chose between the top three candidates for President. A majority of states is required with each state casting one vote. The Senate will choose the Vice President from the top two candidates with a majority of Senators required.  

House deadlocks on the Presidential vote. This vote will occur on January 6, 2021 after the new Congress is sworn in. Since we don’t know the exact composition of the new House we will have to make some assumptions. I think it’s safe to assume, especially if the Presidential election is close, the composition of the House will be similar to what it is now. Currently Republicans control 26 state delegations and Democrats 24, with Pennsylvania and Michigan evenly split. Let’s assume Democrats maintain the overall majority and Republicans lose control of just one state delegation. This could happen in Montana, where the race for the lone seat is currently a tossup, or in Florida where Republicans hold a one seat advantage and several races could go either way. Even if the Republicans maintain control of a majority of state delegations, it is possible one or more states could withhold support for Trump. It could take as little as one member choosing to follow the vote of their state or the overall popular vote instead of backing the party. In any event, it is quite possible neither party is able to muster the votes of the 26 states required to select the President.  

Senate selects the Vice President. Also on January 6, 2021, the new Senate will select the Vice President. Currently the Republicans hold 53 seats, but there are several Republican held seats currently considered tossups. A 50-50 Senate is definitely a plausible outcome of the 2020 election. Assuming all of the Senators toe the party line, the vote would be tied. This would require some Senators to vote against the choice of their state, one party to vote against the popular vote, and Kamala Harris to vote for herself. Given these considerations, even if Republicans maintain a slim majority the vote could end in a tie. Article 1, Section 3 of the Constitution allows the Vice President to cast the deciding vote when the Senate is tied. Mike Pence, as the sitting Vice President, could cast the deciding vote to secure his re-election as Vice President. 

House remains deadlocked on inauguration day (January 20, 2021). In the two weeks between the initial House vote and the inauguration, the House could continue to vote or they could accept the deadlock. It is possible they could work out some sort of compromise giving the Presidency to one candidate in exchange for some policy concession; this is more likely with a wider popular vote margin. But assuming this doesn’t happen, the 20th Amendment states the Vice President Elect (Pence) “shall act as President until a President shall have qualified.” So on January 20, 2021 Mike Pence would become the President of the United States due to his tie breaking vote in the Senate.