This is the fourth post in a series. The first one is here. The second, here. The third, here.

There are many scenarios that could yield bizarre outcomes in our presidential election--largely turning on facets of the Electoral College. While Hillary Clinton's lead has grown steadily in recent days, FiveThirtyEight keeps track of some of these scenarios, including the not-so-implausible likelihood of an electoral vote tie, 269 for Donald Trump and 269 for Mrs. Clinton.

(It's worth noting that this possible two-party tie is a direct result of the Twenty-Third Amendment, which assured the District of Columbia a number of presidential electors equal to the fewest number of electors given to a state--now, three. The Senate always has an even number of Senators, because each state receives two, and the Vice President votes in case of a tie. The House of Representatives is designed to have an odd number of Representatives to avoid ties. An odd number plus an even number equals an odd number--right now, 100+435=535. But adding the odd number of three electors to this odd number means there will be an even number of presidential electors.)

The pressures and alliances may grow bizarre in a close election.  Suppose Mr. Trump secured 270 electoral votes and Mrs. Clinton 268. A single faithless Trump elector could cast a vote for Mrs. Clinton, tie the election at 269, and send the race to the House. (Two such faithless electors could swing the election to Mrs. Clinton.) Or a single faithless Trump elector could cast a vote for Paul Ryan, leaving the vote totals among Mr. Trump (269 votes), Mrs. Clinton (268 votes), and Mr. Ryan (1 vote).

Another poll showed Libertarian candidate Gary Johnson within striking distance of the lead in New Mexico, leading a possibility that Mrs. Clinton wins 267 votes, Mr. Trump 266, and Mr. Johnson 5.

In the event that no candidate secures a majority of the electoral votes when the Electoral College gathers on December 19, it is left to the new Congress, and the newly-seated House, to choose the next president. Each state receives a single vote. Yes, Wyoming gets the same vote as California, and Rhode Island gets the same vote as Texas, just the way the states voted in Congress under the Articles of Confederation.

In the single-vote-Paul Ryan scenario, it would be within the House's power to vote for Mr. Ryan, hearkening back to 1824 as a time when the person who failed to secure the most electoral votes still won the presidency. Or to vote for Mr. Johnson in the New Mexico scenario. The House has the opportunity to consider the top three electoral vote-getters--surely adding pressure for a faithless elector in a 269-269 scenario to defect toward a third candidate and give the House an additional option. (It's worth noting that the Constitution provides no assistance in the event of a tie for the third-place vote-getters, meaning that perhaps more than three candidates would be options for the House.)

There is little doubt, I think, that the House, which has a fair majority of Republican-controlled delegations, would select Mr. Trump. As tempted as they might be choose their own Speaker, Mr. Ryan, the cries of illegitimacy would be strong. And if the "establishment" Republicans failed to stop Mr. Trump at the national convention--the most logical place to prevent his candidacy from moving forward--surely it would fail to do so here, too.

The Framers expected that the House would regularly have the opportunity to choose among the top vote-getters as they doubted that candidates would regularly secure a majority of the electoral votes. But the quick rise of our two-party political system changed that calculus--most (often, essentially all) electoral votes went toward one of two candidates, which dramatically increased the likelihood of a winner without a role for the House.

In the event the House does decide a presidential election, reform efforts are quite likely to follow. An expectation of popular involvement in our election, not of the House, would drive that. But, much like the role of electors, the role of the House remained a part of the Twelfth Amendment and our first reforms of the Electoral College--even though the House cast 36 ballots in 1800 before choosing Thomas Jefferson as our third president.

In the unlikeliest of scenarios, the Senate chooses between the top two vote-getters for the next vice president, and lingering uncertainty in the House might make this person the Acting President as the House sorts out its election. And it creates the possibility of creative or unusual presidencies, like Johnson-Kaine or Ryan-Kaine.

And while the House or Senate choosing the next president is not an optimal outcome (at least, if you're among those who yearns for popular elections and increasingly direct democracy), consider what should happen if no candidate secures a majority. A run-off, a second election? Or reform for some kind of ranked choice or instant run-off voting? Or simply permit a candidate with a plurality to win an election? For while the House choosing the next president seems problematic, serious thought must go into deciding what system ought to replace it--and, perhaps, presents its own challenges.