In 1780, founding father John Adams expressed in a letter his disdain for a two-party political system.
There is nothing which I dread so much as a division of the republic into two great parties, each arranged under its leader, and concerting measures in opposition to each other. This, in my humble apprehension, is to be dreaded as the greatest political evil under our Constitution. We cannot have a bad Governor at present. We may not possibly have the best that might be found, but we shall have a good one; one who means to do no evil to his country, but as much good as he can.
In U.S. history we have almost always had two great parties. George Washington had no party, and Adams became the second president under the Federalist Party, which led to the creation of the Anti-Federalist Party.
The Federalists favored central government control by educated, elite society members. They were basically Democrats (and in fact eventually became Democrats in 1829). The Anti-Federalists watered themselves down and eventually transmogrified into the Whig Party, which failed due to its wishy-washy stance on slavery.
In the intervening years after the Federalist/Anti-Federalist period until the rise of the Democrats and Whigs/Republicans there was a miasma over national political parties. From 1815 through 1832 we had a period where it was every man for himself. This culminated in the presidential election of 1824 when John Quincy Adams, Henry Clay, Andrew Jackson and William Crawford competed in a 4-way struggle. Going into the general election, there were six good and serious candidates in the race. Nothing (so far) more closely resembles 2016 than 1824 did in that respect.
No candidate achieved an electoral majority in the 1824 election, and the race was thrown into the House of Representatives in 1825. Jackson had both the most electoral and popular votes, but lost in the House (in no small part due to Speaker of the House Clay, who hated him, throwing his support to Adams).
The 1824 election had no parties at all; everyone ran under the banner of “Democratic-Republican.”
This brings us to today’s situation. A truly unacceptable candidate to many citizens, Donald Trump, is on the precipice of hijacking the Republican Party. In the process of doing that, he will likely destroy the GOP, at the national, and eventually, the state election level. If he doesn’t outright destroy it through the rise of a third party, he will damage it so severely that the Democrats will enjoy many years of liberal hegemony while the GOP morphs from its own ashes into something meaningful.
The strident call coming from the Trump camp is “support the party, support the man.” But no, we refuse that, because the man is not worthy.
George Washington himself deemed it our duty to constrain parties which go off the rails.
The alternate domination of one faction over another, sharpened by the spirit of revenge, natural to party dissension, which in different ages and countries has perpetrated the most horrid enormities, is itself a frightful despotism. But this leads at length to a more formal and permanent despotism. The disorders and miseries, which result, gradually incline the minds of men to seek security and repose in the absolute power of an individual; and sooner or later the chief of some prevailing faction, more able or more fortunate than his competitors, turns this disposition to the purposes of his own elevation, on the ruins of Public Liberty.
Without looking forward to an extremity of this kind, (which nevertheless ought not to be entirely out of sight,) the common and continual mischiefs of the spirit of party are sufficient to make it the interest and duty of a wise people to discourage and restrain it.
If the GOP nominates Donald Trump, the GOP will pay for that nomination with its own soul and blood. It’s the duty of principled people who disagree to move to another vehicle for their cares and values to be championed by another figure who is better able to do so. Not just better, but in any way qualified over the party they abandon to its own folly.
This has happened before in the life of our Republic. Should Donald Trump take the GOP mantle, there absolutely should be a third party candidate to challenge him on behalf of conservatism as a movement. It’s also likely that Michael Bloomberg would enter the race on his own as a more centrist alternative to Hillary or Trump.
We could find ourselves in a 4-way general election, close but different than the one Brian Miller posited. Instead of Cruz for the GOP and Trump as an independent, along with Hillary and Bloomberg, we could have Trump for the (now zombie) GOP, and some other conservative (Erick suggested Rick Perry) for the new third party.
Whether this would end in the House of Representatives or not is yet to be determined. But one thing would be clear: the two-party system as we know it will be dead, and we will again enter an “every one for themselves” period. The last time this happened a civil war precipitated a return to a two-party system.
This time, whether our country can recover from it is a question our children will have to answer.