In this extraordinary presidential election, when the presumptive nominees of both major parties have historically low approval ratings, many Americans are looking for other options. But the structural obstacles facing third-party and independent candidates — ranging from campaign-finance regulations to ballot-access rules — prevent viable alternatives. Add in the common sentiment that a vote for someone other than a Republican or Democrat is “wasted” and it’s clear that, assuming they do get their respective parties’ nomination, nobody other than Donald Trump or Hillary Clinton has a chance to win, right?

Actually, it’s not so simple. While it’s inconceivable that anyone other than the major-party candidates could win the popular vote, it’s possible that nobody wins a majority in the electoral college. If there’s no electoral majority, the 12th Amendment specifies that the House of Representatives, voting by state, will choose the president among the top three. It’s only happened once — in 1824, when John Quincy Adams won despite Andrew Jackson’s having gained popular and electoral pluralities — but it’s not too much to expect in this bizarre political year.