In the 1850s, the Whig Party faced intense pressure over the issue of slavery. Unhappily for would-be unifiers like Mitt Romney, the Whigs had much in common with the present-day GOP. They represented a patchwork of interests; they were bitterly divided geographically, and they were right of the political center.

Beginning in the late 1840s, the Whigs suffered defections to splinter parties such as the Free Soil Party. When a viable new alternative, the Republicans, were organized in 1854, the Whigs completely dissolved.

Fearing a similar dissolution, Peggy Noonan, the columnist (and former Ronald Reagan speechwriter), wrote last week in the Wall Street Journal that “Something important is ending.” She confessed to anger and conveyed great sadness. And this, of course, was before this week’s “Super Tuesday 2,” when Trump’s victories in Michigan, Mississippi and Hawaii solidified his lead in the race for the GOP nomination.

The Republican fiasco of 1912 might cheer her. Yes, the party cracked that year, but the egg was put back together. And for sheer drama, the campaign of 104 years ago matched that of today.

The 1912 election was one of the last to feature a truly “brokered” convention–and that occurred among the Democrats, where Woodrow Wilson, the governor of New Jersey, eventually beat Champ Clark, speaker of the House, on the 46th ballot.

But the real circus was among the Republicans. Theodore Roosevelt, a former president, rebelled against the incumbent, the modest former jurist William Howard Taft. Not only was Taft a fellow Republican, he was Roosevelt’s political protégé and handpicked successor.

As today, the electorate was aroused by economic issues and angered by unequal distribution of income, exemplified back then by the spread of “trusts” (that is, monopolies). Roosevelt, who believed Taft was too soft on corporate interests, appealed to the progressive vote, campaigning on Taft’s left. He waged a fierce campaign against his friend in states with primaries, generally winning them.

But somehow, Roosevelt’s challenge was as much about his charismatic personality as it was about issues. Though not as outrageous as Trump, T.R. was an outsized egotist who shot from the hip and on occasion stooped to demagoguery. When party bosses handed the nomination to Taft, Roosevelt proclaimed he had been cheated—didn’t Trump say something similar after Iowa?—and formed his own party.

The parallels to Trump stop there. Roosevelt was a consistent progressive over his career, also a prolific writer and naturalist, hardly calling to mind the casino mogul. And Roosevelt, a war hero, was genuinely courageous. While on the stump in 1912, T.R. was shot; he refused to cancel a speech, even with his chest oozing blood, telling his stunned audience, “It takes more than that to kill a bull moose!”

However dramatic, Roosevelt’s third-party bid handed the election to the Democrats and Wilson. And there, the Republican fissure ended. Roosevelt was grumpily reconciled with the party. Wilson served two terms, after which the Republicans reassumed what had been their dominant political status, winning three consecutive elections.

Both the Whigs and the Wilson-era Republicans faced political convulsions. Why did only the Whigs perish? The party of Henry Clay was reasonably coherent. Its main planks—a protectionist tariff, a central bank, and government support for railroads and canals—all fit under the mantle of economic nationalism. True, the Whigs also attracted social reformers, temperance types and anti-Catholic nativists—but these it could survive. At the center of the party was an agreement not to engage the slumbering issue of whether to permit the extension of slavery. With the Compromise of 1850, the subject could not be avoided. The party’s southern and northern wings hopelessly split.

The GOP of 1912 did not so much survive as assume new colors. Prior to World War I, Republicans were the internationalist party; Democrats were isolationist. World War I changed all that. By the 1920s, although a core of influential internationalists, especially on Wall Street, remained in the GOP, the party came to espouse the narrow isolationism, often tinged with bigotry, that would resist rearmament in the 1930s. Similarly, prior to 1912 the Republicans were generally the more “progressive” party—more liberal and more open to an expanding federal role in the economy. In the ‘20s, the GOP retreated to laissez faire.

The Democrats, responding to the progressive movement, made a converse flip. They embraced government regulation of corporations and social reform, and thus slipstreamed the Republicans to the left. The point is that, to endure, political parties now and then have to adapt. Coalitions aren’t forever.

The Taft Republicans were well-positioned to endure; they had won nine of eleven elections since the Civil War. (The Whigs, overmatched by Andrew Jackson’s Democrats, had no majority to fall back on.)

Today’s Republicans might take comfort. They won seven of ten presidential races prior to 2008, and even during the Obama years they’ve steadily advanced in both houses of Congress and also gained 900 state legislative seats and 11 governorships.

But what exactly do they stand for? They are surely less coherent than Henry Clay’s Whigs. No logic explains why social conservatives, small-government purists, free traders, immigration refuseniks, foreign policy hawks and (with Trump) economic populists should all belong to the same party.

Admittedly there is no issue convulsing the GOP as slavery did in the 1850s, though discontent with the economy may come close. Trump has found a convenient scapegoat—immigrants—for slow growth, but not a cause. But this discontent is fueling a populist rebellion, on the left and on the right, not wholly dissimilar from the progressive upheaval of 1912. Moreover, in the full-primary era, parties can change whether or not their leaders want them to.

The lesson of history is that parties must adapt. The question for the Republicans is whether there is any shape that can fit a suitable number of them.