|U.S. Electoral College--538 Electors; 270 needed to win|
Under the United States constitution we don't elect presidents by popular vote. For example, George W. Bush lost the popular vote to Al Gore in 2000, but he nevertheless won the presidency. That is because Bush won the electoral college vote, thanks to some hanging chads in Florida, an assist from strong-arm on the ground politics, and perhaps the Supreme Court.
The Electoral College
The electoral college is a compromise between having the president elected by Congress and having the president elected by popular vote.
U.S. Constitution, Article II
Section 1. The executive Power shall be vested in a President of the United States of America. He shall ... be elected, as follows:
Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress.... The Congress may determine the Time of choosing the Electors, and the Day on which they shall give their Votes; which Day shall be the same throughout the United States.
Twelfth Amendment. The Electors shall meet in their respective states, and vote by ballot for President and Vice-President, one of whom, at least, shall not be an inhabitant of the same state with themselves; they shall name in their ballots the person voted for as President, and in distinct ballots the person voted for as Vice-President, and they shall make distinct lists of all persons voted for as President.... The President of the Senate shall, in the presence of the Senate and House of Representatives, open all the certificates and the votes shall then be counted;
The person having the greatest number of votes for President, shall be the President, if such number be a majority of the whole number of Electors appointed; and if no person have such majority, then from the persons having the highest numbers not exceeding three on the list of those voted for as President, the House of Representatives shall choose immediately, by ballot, the President.
But in choosing the President, the votes shall be taken by states, the representation from each state having one vote; a quorum for this purpose shall consist of a member or members from two-thirds of the states, and a majority of all the states shall be necessary to a choice....Any credible third party candidate would split the vote. Ross Perot, the last serious third party candidate received 19% of the vote in 1992. But because his votes were relatively evenly distributed around the country, this was not sufficient for Perot to win any electoral votes. Bill Clinton won the electoral college over George H.W. Bush with 43% of the popular vote.
Potential for Third Party Candidates
This year there is the potential for a genuine third party candidate who might win some electoral college votes. Michael Bloomberg, the billionarire ex-mayor of New York, is contemplating a run. His potential run is viewed favorably by the Tech industry.
Early on the GOP worried about Trump running as a third party candidate if he did not win the GOP nomination. Now, if Donald Trump winds up winning the Republican nomination against the will of the Republican establishment, it seems conceivable that the Republican establishment might run Bush or Rubio or Kasich as an independent. [I've heard no suggestion to this effect and such speculation seems premature, but still....]
A strong independent run from Bloomberg, and/or an establishment Republican running against a Trump GOP nominee, might well garner sufficient Electoral College votes to deprive both the Democratic nominee and the Republican nominee of an Electoral College majority.
If the Electoral College vote does not result in a majority for a candidate the election is thrown to the House of Representatives. The House would choose among the top three candidates (receiving votes in the Electoral College), but it would do so by state. One vote for each state.
Determining the vote for each state would prove interesting. The Congressional representation from each state would come into play, as well as the party representation in the state governments.
Here is Norman Ornstein of the American Enterprise Institute, who thinks a strong independent presidential candidate would be a nightmare:
For an independent candidate, at best, it would mean three candidates splitting the popular vote, probably roughly a third apiece, with the independent edging out the others with perhaps 35 percent. ... An independent might well secure some electoral votes, but in such a race, no candidate would come close to the majority of 270 required, under the Constitution, for victory.
What then? The Constitution says that if no candidate gets a majority of electoral votes, the election moves to the House of Representatives, among the top three electoral vote-getters. There is a twist: House members do not vote individually but by state, a majority of which are required to select the president. Currently, 33 states have House delegations that are majority-Republican; three are evenly split; and Democrats control 14. ....
The states themselves would have to caucus individually to determine how their votes would be cast. Members might vote for the winner of the popular vote, or the winner of the vote in their own districts, or the winner of the vote in their states, or based on partisan loyalty. Multiple ballots could be required. But the odds would be great that, in the end, the House would choose the candidate whose party controlled the most delegations.
Whatever the outcome — an independent ultimately elected president but without a single lawmaker with any attachment to him or her; or a partisan, probably a Republican, chosen primarily because of the partisan tilt of gerrymandered districts — it would not be healthy for the country. A president elected this way would limp into office lacking legitimacy via a process ripe for logrolling and corrupt bargaining. (Read the history of the 1824 election, for example.)
There are reasons to despair over the trajectory of our presidential election process, and of our political process more generally. That trajectory would not be positively altered by a prominent independent candidate parachuting into the 2016 presidential race or being force-fed into the fall debates.