I was hiking a rock-strewn dirt trail in the Arizona desert when I learned that Kevin McCarthy's candidacy to succeed John Boehner as Republican speaker of the House had crumbled into dust. It was a very 21st-century moment — and not just because I got the news on my cell phone while on vacation in the middle of nowhere, miles away from any town or television screen. The news itself also served to confirm the singular political fact of our times: the collapse of the GOP into something less than a political party.

In its obsession with flamboyant displays of ideological purity, in its unwillingness to compromise and its fondness for brinksmanship, in its subversive disregard for institutional norms and restraints — in all of these ways, the Grand Old Party is transforming itself before our eyes from a party into a faction.

Both forms of political organization — party and faction — express the interests and ideological outlook of one part of a political community. But that's where the similarity ends.

A faction aims solely to advance the interests and ideological outlook of its members. It fights for total victory. It doesn't compromise. Special-interest groups are probably the most obvious example of factionalism in action. The NRA never suggests that modest gun control would be acceptable, just as Planned Parenthood never declares that it would be content with moderate restrictions on late-term abortions. Both organizations stake out maximal positions and aim to take down anyone who deviates from them.

Parties are different — or at least they're supposed to be in presidential systems like our own, with "winner take all" electoral rules that grant complete victory to whichever candidate (and party) manages to win a plurality of the votes in a given election.

In such systems, parties are supposed to function as coalitions of factions that join together under a broad ideological umbrella. The party seeks to obtain and hold on to political power in order to advance an agenda favored by the factional members of its coalition.

This requires and presumes a willingness on the part of the party's factions to compromise and get along with people who sometimes have quite different passions, interests, and agendas. There's nothing obvious that would put the religious right, economic libertarians, and foreign policy hawks together in the same party, just as there's no reason to presume that those who favor higher levels of government spending and regulation, strict separation of religion and politics, and a more restrained use of American military might around the globe would congregate under the same partisan tent. That's just the way things have shaken out historically in the U.S.

But more significant than the historically contingent members of each party's coalition is the fact that the partisan factions are supposed to work together, suppressing the drive to pursue an all-or-nothing agenda at the expense of the other members of the coalition, let alone at the expense of the party as a whole. Each member of the coalition is supposed to recognize that, in a winner-take-all system, every faction is better off working together as a team than aiming to enact a list of uncompromising demands.

In parliamentary systems with proportional representation, the (often smaller and ideologically narrower) parties are freer to behave like factions, because the process of compromise and conciliation happens later in the process — after the election. That's when various parties come together to form a government and leave their factional tendencies behind. But in our presidential system, there is no institutional process of conciliation after Election Day. If the party has failed to band together prior to an election, it's unlikely to happen afterwards.

What we've been seeing since 2010 is a growing factionalization of the Republican Party. The Tea Party (or so-called Freedom Caucus in the House), along with the voters who support it, is a faction within the GOP that has no interest in acting like a member of a party. It wants to get its way or else assure that no one else does — both within the party and in clashes with the Democrats.

The GOP as a whole doesn't share the ideological fervor of the Tea Party faction. But, as we've seen in a series of budgetary and debt-ceiling showdowns since 2011, and most recently with the sacking of Boehner as House speaker and collapse of the McCarthy candidacy to replace him, this faction has sufficient power to drive the party into a ditch rather than permit it to govern in a way that deviates from the faction's preferences. By throwing wrenches, derailing deals, gumming up the works of government, throwing hissy fits whenever someone proposes a compromise, and lending support to any candidate who promises to overturn the Republican establishment, the Tea Party faction is succeeding in making the GOP as a whole act more like a faction than a party.

That's cause for concern. Constitutional government in a presidential system depends on the regular alternation of power between competing parties, each of which channels, balances, and synthesizes disparate factional tendencies into a national vision of governance and the common good. At the moment, the United States appears on the verge of having only one party capable of fulfilling that vital, indispensable civic function.

In the short run, this might be good news for the Democrats hoping to win the White House in 2016. But in the long run it's bound to be bad for the country as a whole — which is likely to see increasing dysfunction in Washington, as the Grand Old Faction adopts ever more extreme tactics to sabotage government, thereby inspiring more of the very discontent with the status quo that fuels its factionalism.

The sad and somewhat scary truth is that the Republican faction doesn't have to win in order to succeed in its aims.