Law Stack Exchange is a question and answer site for legal professionals, students, and others with experience or interest in law. It only takes a minute to sign up.
Sign up to join this community
Specifically, what branch of the federal government would need to be involved most to change the presidential voting system from its current electoral college, first-pass-the-post model to a popular instant-runoff voting model?
And what is the best course of action for an individual to take to make that happen (short of befriending a billionaire or running for office)?
Since electors are in fact free to vote for whoever they want (though don't usually deviate from their assignment), the branch of federal government that would be most involved is Congress. A constitutional amendment would be required, to repeal Article II Section 1 Clauses 2 and 4 and the 12th Amendment (i.e. eliminate electors entirely), and substitute a different method. Most of the work would be done by the states, in ratifying the amendment.
[Addendum]
It is true that it is constitutional to require a pledge of faithfulness (Ray v. Blair 343 U.S. 214). A bit over half of the states have laws requiring 'faithful voting', though the laws have not been enforced. Washington RCW 29A.56.320 may be typical, in that the law simply says "thou shall" with no mechanism for enforcement. Even with strict enforcement such as class X felony penalties, this cannot implement IRV. The number of electors is not proportional to population (there is the "plus 2 for senators" factor), and various other reasons why state-based electors cannot be morphed into an IRV-like system.
The current system for electing the president can be changed by the states without a constitutional amendment.
The National Popular Vote proposal would ensure that the candidate with the most votes in all 50 states and DC would be elected president. It is a state law, under which states agree that they will assign all of their electors to the candidate who has the most votes in all 50 states and DC. It does not go into effect until enough states have ratified it that that candidate will be sure to win. That will be when the states that have passed it collectively have at least 270 electoral votes. It has already been enacted in 11 states with 165 electoral votes.
So the system can be changed to a national first-past-the-post (usually called plurality) election without any change to the U.S. Constitution. However, that will not make it possible to elect nationwide by instant runoff voting (usually called ranked choice voting). Because that would require every state to use the ranked ballot, and to coordinate centrally to determine the winner, it would take a constitutional amendment.
To get involved with the movement for the National Popular Vote proposal, check out www.nationalpopularvote.com. To get involved with the movement for ranked choice voting, check out www.fairvote.org.
