House Speaker Kevin McCarthy and others arrive at a rally marking the 100th day of Republican control of the House of Representatives at the U.S. Capitol on April 17, 2023. (Nathan Posner/Anadolu Agency via Getty Images)
House Speaker Kevin McCarthy and others arrive at a rally marking the 100th day of Republican control of the House of Representatives at the U.S. Capitol on April 17, 2023. (Nathan Posner/Anadolu Agency via Getty Images)

House Republicans are working with one of the narrowest margins in U.S. history. Following the election of Democrat Jennifer McClellan to fill a vacant seat in Virginia, they have just a nine-vote edge on Democrats, 222 to 213 (or 2.06 percentage points) – even slimmer than the Democrats’ House majority in the previous Congress, and the tightest margin in nine decades.

Slender House majorities (which in this analysis we’re measuring as of the first business day of each Congress) have become more common in the past few decades. After a long run of comfortably large Democratic House majorities from the late 1950s through the early 1990s, narrow majorities – defined for this analysis as margins of control of fewer than 5 percentage points – have prevailed in a third of the 15 most recent Houses.

In fact, the 2.3 percentage point edge that House Speaker Kevin McCarthy’s Republicans held at the start of the current Congress is the fifth-smallest in U.S. history, tied with the 107th Congress of 2001-02 and the 83rd Congress of 1953-54. That means McCarthy is under tremendous pressure to keep his caucus – especially the four dozen or so members and allies of the House Freedom Caucus – in line.

How we did this

Given the thin Republican majority in the new House of Representatives, Pew Research Center conducted this research to learn about similar situations in the past and how they played out.

For each Congress, we took as our reference point the first day the House actually convened to organize itself and begin its legislative work. We calculated the difference between the majority- and minority-party shares of the House’s total voting membership; to make the differences comparable across Houses of varying size, we then expressed them in percentage-point terms. Any difference of less than 5 percentage points was considered a “narrow majority” for the purposes of this analysis. In a handful of cases where the majority comprised an alliance of two or more parties, we used that total instead.

For the 74th Congress of 1935-36 and onward, this process was fairly straightforward. That was when Congress began to convene at the official beginning of its term in early January, less than two months after the November elections. For each of those Congresses, we compared the party division figures in the House Clerk’s biannual election reports with those reported by the House historian and on each Congress’ Wikipedia page. If there was any discrepancy between those three sets of figures, we downloaded a list of all members who served in that Congress from the Biographical Directory of the United States Congress and determined who was actually in office on the date it first assembled.

A line chart showing that narrow majorities in the U.S. House are nothing new.

There have been a few other periods in U.S. political history when closely divided Houses were more common. Of the seven Congresses that met between 1877 and 1891, for example, four had narrow majorities, as we define them. So did three of the six Congresses that met between 1839 and 1851.

The closest margin of all, though, occurred in the 65th Congress of 1917-19. After gaining seats in the 1916 elections, Republicans had, on paper at least, a 215-213 edge over Democrats (including one “independent Republican” and a self-described “independent Progressive Republican”) when the new House met for the first time on April 2, 1917.

But since neither party had a majority, the balance of power was held by four representatives from minor parties – two Progressives, a Socialist and a Prohibitionist. They joined with the Democrats and the “independent Progressive Republican” to reelect Champ Clark of Missouri as speaker, thus enabling the Democrats to – just barely – retain control of the chamber, by a margin of less than half a percentage point.

House Republicans got the short end of the stick again in 1931, during the 72nd Congress. When that Congress’ term officially began on March 4, Republicans had a one-seat majority – 217 to 216, with one member from Minnesota’s Farmer-Labor Party and one vacancy. Unfortunately for the Republicans, the House wouldn’t actually meet to organize itself and start legislative business until Dec. 7. By that time, Democrats had flipped three GOP-held seats in special elections and gained a 219-214 majority (or 1.15 percentage points). The Democrats swiftly used their majority to elect John Nance Garner of Texas as speaker and control the House.

A table showing that the Republican majority's margin in the 118th House is tied for fifth-closest ever.

Close speaker elections nothing new

Narrow majorities are tailor-made for contentious speakership elections, as McCarthy’s weeklong, 15-ballot grind in January demonstrated. But considering some of the bitter, drawn-out partisan battling that marked some pre-Civil War elections for speaker, McCarthy’s election almost looks smooth by comparison.

Take the 26th House, which convened on Dec. 2, 1839, and promptly ran aground on the question of which of two competing New Jersey delegations, six Democrats or six Whigs, should be seated. (At the time, New Jersey elected all of its House members on a single “general ticket” rather than from individual districts. Irregularities in the returns from a few localities created confusion as to which slate of candidates actually had received the most votes.) Without the New Jerseyans, House Democrats had a slight numerical edge over the Whigs and their allies, but seating either delegation would effectively give one party or the other control of the chamber. After several acrimonious days of debate, the House (which under the Constitution is the sole judge of the “elections, returns and qualifications” of its members) decided to defer the whole New Jersey question, which would seem to have given Democrats the upper hand.

But the Democrats were divided among themselves and couldn’t agree on a single candidate for speaker. On the 11th ballot, the House finally settled on Robert M.T. Hunter of Virginia, who was nominally a Whig but acceptable to some (mostly Southern) Democrats.

A decade later, another splintered Congress, the 31st, took nearly three weeks and 63 ballots to elect a speaker. Although Democrats had a four-vote (or 1.73 percentage point) edge on the Whigs, each of the major parties contained pro- and anti-slavery members – a divide that largely, but not entirely, followed North-South lines. Anti-slavery Democrats refused to vote for their caucus’ nominee, Howell Cobb of Georgia, while the Whig nominee, Robert Winthrop of Massachusetts, lost both pro- and anti-slavery members of his own caucus. Another complicating factor was the presence of nine members from the Free Soil Party, the only unequivocally anti-slavery party at the time. In the end, the House could break the deadlock only by abandoning the majority-vote requirement entirely. Cobb beat Winthrop for the speakership by three votes.

Can anything get done?

While a narrowly divided House may make passing major legislation harder, it doesn’t automatically condemn Congress to achieving nothing of significance. A review of past Congresses suggests that having same-party control of all three legislative actors – the House, Senate and presidency – certainly helps, as can the spirit of unity engendered by wars or other crises.

In the 107th Congress of 2001-02, for example, Republicans had just a 10-seat (2.3 percentage point) margin in the House, and the Senate was so closely divided that control swung from Democratic to Republican and back again in the space of six months. Nevertheless, that Congress enacted the Bush tax cuts, the No Child Left Behind education law, a campaign-finance overhaul and new rules for public-company accounting – not to mention a raft of laws responding to the 9/11 terror attacks.

More than a century earlier – in the 51st House of 1889-91 – the GOP won a narrow majority (nine seats, or 2.73 percentage points) after several years of divided government, giving the party control at both ends of Pennsylvania Avenue. Republicans lost no time in enacting much of their party platform into law, including raising tariffs, expanding eligibility for Civil War pensions, extending the land-grant college system to the South, and creating both the first national forests and the federal appeals courts.

But when the government is divided and one party has only a tenuous grip on the House, it’s often been the case that little to nothing of substance is accomplished. Perhaps the best example is the 19th Congress of 1825-27.

The formerly dominant Democratic-Republican Party had collapsed into factions, mostly gathered around President John Quincy Adams and former Gen. Andrew Jackson, the man whom Adams had edged out in the 1824 presidential election. When he took office, Adams faced a Senate dominated by Jackson supporters and a House where “Adams men” held a three-seat (1.41 percentage point) majority. The new Congress “aggressively opposed” Adams’ policies, according to the House’s official historian, and “more or less simply marked time before the next presidential election [in which Jackson handily defeated Adams] by voting down administration proposals.”

Drew DeSilver  is a senior writer at Pew Research Center.