Despite unified control of the House, the Senate and the White House, few legislative accomplishments come to mind. A bitter conflict between a president with little interest in party loyalty and a career politician running the Senate.

No, this particular story isn’t about Donald Trump and Mitch McConnell. But Republicans wondering just how bad things can get should take a close look at another episode of Washington history that suggests the worst is yet to come.

In 1841, President John Tyler was engaged in a bitter feud with Henry Clay, the de facto leader of the Senate, that was brutal for both sides — and to the party they both belonged.

Politics in the 1830s had been defined by the clash between Andrew Jackson, a Democrat, and his opponents, who eventually coalesced as the so-called “Whig Party.” The Whigs, who counted Kentucky’s Henry Clay among their leaders, found themselves outplayed at almost every turn by Jackson.

Whigs hit the trifecta in 1840, capturing the House, the Senate, and the presidency, which went to William Henry Harrison and his running mate, Tyler.

Fast forward to the spring of 1841, when Harrison gave the longest inaugural speech in history, standing out in the cold March snow and rain without the benefit of a coat or hat. He fell ill and died a month later.

Clay, now presiding over the Senate, was disappointed in Harrison’s death, but figured he could get Tyler to support the Whig legislative program. Stymied by years of Democratic rule, the Whigs practically salivated at the prospect of finally turning their many plans into action, most important of all a new national bank (Andrew Jackson abolished the last one).

But when Clay pestered Tyler about the bank, Tyler demurred, finally losing his patience and sending Clay on his way.

Tyler’s rejection carried only so much weight with Clay, who commanded strong majorities in both houses of Congress. Clay commandeered the legislative program, writing up a bank bill that ignored Tyler’s concerns, daring him to veto a bill passed by his own party. Tyler did just that.

Congress tried yet again to resurrect the national bank, hoping to find a compromise that made everyone happy. Then Clay stood up in Congress, blasted Tyler, and accused of him of being of a tool of the Democratic Party. Tyler promptly vetoed it.

Whigs excoriated Tyler, labeling him a “vast nightmare over the republic” and formally expelled him from the party. Clay and other Whig leaders began plotting to force Tyler from power.All of Tyler’s cabinet but one, Daniel Webster, hailed from Clay’s faction. And on September 11, 1841, everyone but Webster resigned, believing that the dramatic exodus would drive Tyler from power.

Nothing of the sort happened; nor did a push for impeachment succeed. Tyler swiftly selected a new cabinet that consisted of Whigs outside of Clay’s circle. And Tyler continued to veto anything that Clay touched, though he did sign off on some pieces of Whig legislation. dividing the Whigs even more and emboldening the Democrats. In midterm elections, the Whigs lost seventy seats in the House.

Toward the end of his term, Tyler sought to create a new party. He called it the new “Democratic-Republican” party, and prepared to seek its nomination for president in 1844. The Whigs countered by nominating Henry Clay, while the Democrats bet on a dark-horse candidate, James Polk of Tennessee. Polk won the election by a mere eight thousand votes. The Democrats also won the House and Senate.

The Whigs did not recover from Tyler’s presidency. They never recaptured the Senate, and only briefly held a razor-thin majority in the House. The Whig Zachary Taylor won the presidency in 1848, but died a little over a year into his term, replaced by another accidental president, Millard Fillmore. By the end of Fillmore’s term, the Whigs went extinct.

It’s a story that today’s Republican party should study. They may believe that they can contain the damage wrought by the unpredictable, former Democrat who now leads their party and the nation. But history suggests that we may be at the very beginning of a long, painful unraveling.

Buckle up.

Stephen Mihm, an associate professor of history at the University of Georgia, is a contributor to Bloomberg View.