WHICH OF THE TWO MAJOR POLITICAL PARTIES is stronger? Until President Joe Biden decided to withdraw from consideration as his party’s nominee, it looked like the GOP was the obvious answer. But Donald Trump remains a deeply flawed and unpopular candidate. And the Democrats’ ability to put the party’s (not to mention the country’s) interests before its leader’s suggests that of the two institutions, it is the stronger.

As of now, Trump still looks to be the favorite against Kamala Harris, although that may change quickly as her campaign gets fully underway. But the long-run future of the Republican party is even cloudier. The party is neither as strong nor as weak as it appears. Intolerance for internal dissension makes the party brittle. In the short term, it has the capacity to unify behind Trump and in opposition to Democrats, progressives, the “left,” and a host of common enemies. But in the months and years ahead, the Republican party will face a difficult choice between ideological unanimity and electoral competitiveness. History suggests two possible futures for a party like the current GOP: reform or irrelevance.

Strong political parties contain multitudes. They are able to unite moderates and hard-liners in the same tent, protecting diversity of opinion. There are a few ways this strength plays out in practice: The party apparatus prevents primary challenges to their incumbents from more extreme candidates. Party leadership allows compromise and cooperation with the opposing party to ensure bipartisan legislation. And they permit vulnerable members to break ranks with the party to protect their seats. Strong parties also weed out unacceptable candidates to protect the future health of the party and prevent minority factions from seizing control of the entire operation.

Until recently, the Republican party displayed all of these tendencies. It discouraged primaries against experienced legislators. President Ronald Reagan and Democratic Speaker of the House Tip O’Neill famously compromised on budgets and Social Security. Senator Bob Dole, a fierce partisan and the party’s 1996 presidential nominee, was a lead sponsor of the Americans with Disabilities Act, campaign finance reform, food stamp legislation, and Voting Rights Act extensions—all bipartisan bills. And Republicans used to prevent extreme views from dominating the party. In the 1960s, William F. Buckley Jr. and Sen. Barry Goldwater worked to purge the John Birch Society from the party and the broader conservative movement, rejecting its conspiracy theories and fascist tendencies. As recently as 2019, the GOP punished members for unacceptable positions, including stripping Rep. Steve King of his committee assignments for white-supremacist statements.

But since 2008, the party has witnessed a spike in primary challenges, often from inexperienced candidates touting their “outsider” status. (The Democratic party has also witnessed primary challenges, most notably Alexandria Ocasio-Cortez’s successful primary challenge of Democratic Caucus Chair Joe Crowley in 2018, but at a far lower rate.) Bipartisanship is discouraged to the point that it can end careers, as Sen. James Lankford discovered after his party turned on him for negotiating an immigration reform bill. And formerly fringe elements are now the beating heart of the GOP.

Weak parties eat their own. They devolve into intraparty squabbles, turning their most vitriolic rhetoric on members of their parties deemed “squishy” or insufficiently loyal. As a result, their coalitions often shrink over time, accelerating the radicalization process in a partisan doom-loop.

THAT PROCESS ULTIMATELY DESTROYED America’s first political party, the Federalists. The party’s collapse began in 1799, when President John Adams sent a diplomatic delegation to Paris, hoping to secure a peaceful resolution to the Quasi-War with France. The prospect of peace threatened the Arch Federalists, the party’s extreme faction: Military commissions supported their friends and built valuable political networks, and the urgent threat of war helped the party in elections.

The Arch Federalists spent the next eighteen months attacking Adams and the more moderate wing of the party. Speaker of the House Theodore Sedgwick, an Arch Federalist, referred to the president as an “evil” affliction. In October 1800, Alexander Hamilton published a pamphlet detailing Adams’s flaws, especially his foreign policy, which had “divided and distracted” the Federalists and “furnished deadly weapons” to the rival Democratic-Republicans in the coming election.

Adams lost his re-election bid that fall and the Democratic-Republican party picked up huge wins in Congress. The Federalists never again regained the same electoral or congressional strength. By the War of 1812, the Democratic-Republicans were the only party fielding presidential candidates and had absorbed most of the moderate Federalists into one large party.

Today’s Republican party could undergo a similar radicalization, disintegration, and reorganization. Some of the tendencies of weak parties are visible not just among its party leadership but among the rank-and-file as well. “What I like most about Trump is that he kind of shifted the paradigm of the Republican party away from, you know, guys like Mitt Romney who come in, and they’d say, ‘Oh, we’re going to cut your taxes, but really everything’s going to stay the same,’” said one two-time Trump voter from Texas in a focus group conducted in early 2022. “Trump was a big, loud attack against moderate Republicanism and kind of weak conservatism, and that’s what I like most about him.”

Today, the party faithful call any Republican who criticizes former President Trump a RINO, a Republican In Name Only. Another two-time Trump voter said in an early 2023 focus group that one of the things she liked most about Trump was that, “He’s pointed out the RINOs to all of us and said, ‘These are the people that are causing me heartburn.’” The volatile rhetoric MAGA Republicans hurl at their co-partisans—often including death threats and sometimes escalating to actual violence—has forced many officials to hire private security for their families and driven others from office.

THE DECLINE OF THE WHIG PARTY suggests another historical example of what could happen to the GOP. From the late 1830s to the 1850s, the Democratic and Whig parties fielded candidates across the country. However, as slavery and its expansion in the West grew increasingly controversial, it drove wedges through both parties. The Democrats adopted an increasingly pro-slavery position, driving out anti-slavery Northerners from their party’s ranks, while the Whig party attempted to placate both anti-slavery and pro-slavery factions in its coalition.

By 1850, the status quo was no longer tenable.

The Compromise of 1850 admitted California as a free state, organized the territories of New Mexico and Utah without mentioning their status on slavery, abolished the slave trade in Washington, D.C., and introduced a more punitive Fugitive Slave Act. Northerners were outraged that the new law compelled them to participate in the capture and return of self-emancipated people and recognized that the compromise did little to provide long-term security. Southerners rejected federal “interference” and restriction of slavery in any way.

In response, the Whig party collapsed. As late as 1848, the Whigs had won an Electoral College victory with 47.3 percent of the popular vote. By 1856, the party no longer fielded a candidate. In its place, two anti-slavery factions staked their claims as potential successors. The Republican party nominated John C. Frémont and the rival Know Nothing party nominated former President Millard Fillmore. They split the anti-slavery vote, ushering in James Buchanan as president with just 45.3 percent of the vote.

Four years later, the Republican party had subsumed many of the Know Nothings and formed a coalition of Westerners and anti-slavery Northerners. The Democratic party nominated two candidates—Stephen A. Douglas in the North and John C. Breckinridge in the South. Abraham Lincoln won the presidency with 39.8 percent of the vote.

The Republican party of 2024 could undergo similar fragmentation and fuel the creation of new parties. Recent fights over aid to Ukraine are among the most visible manifestations of deeper divisions in the party. The isolationist wing is suspicious of foreign involvement, the intelligence community, and NATO, while the wing of the party represented by Nikki Haley (at least during her primary campaign) represents a hawkish, internationalist foreign policy.

This intra-Republican divide was visible in the votes in the House of Representatives on the 2024 National Defense Authorization Act and the reauthorization of Section 702 of the Foreign Intelligence Surveillance Act. In both cases—as with the supplemental appropriations for Ukraine, Israel, and Taiwan—the Republican majority relied on the votes of Democrats to overcome Republican opposition. In the “GOP Congressional Report Card” published by Republicans for Ukraine, 111 House Republicans received a grade of D or lower, while 83 received a B or higher.

The divide is visible among Republican voters, too. “I just feel like we’re sticking our nose in something we shouldn’t,” said one Republican focus group participant in August 2023, when asked about supporting Ukraine. “I think we just have other issues here in the United States that we could focus on rather than everyone else.” Another agreed: “America does not need to be the savior of the world. . . . This issue is closer to Europe than it is to us.”

But not everyone saw it that way. “I certainly understand the importance of standing up to Putin and sort of, you know, drawing the line, not allowing Ukraine to just simply be taken,” said another group member. This split roughly corresponds to what the polls show: In a Gallup survey conducted in April, 57 percent of Republicans said the United States was doing too much to help Ukraine, but about a quarter said it was doing the right amount and 15 percent said it wasn’t doing enough.

The Federalist party and the Whig party were destroyed for different reasons. The Federalist party collapsed under the weight of its increasing radicalism, whereas the Whig party dissolved because of its inability to bridge the divide over slavery. But in both cases, a rump party continued to trudge along for a few election cycles while a new one pulled from the old party’s voters as well as disaffected voters in the other party. Before our recent era of durable two-party hegemony, this was the normal boom-and-bust cycle of party politics.

AS THE REPUBLICAN PARTY OF TODAY radicalizes, it turns its vitriol on its more moderate members, forcing them out of elected positions. These retirements and defections force the party even farther right, alienating moderate voters and threatening the party’s future electoral success. History suggests that the Republican party will either make a major course correction or continue to radicalize, turning it into a rump party. The Democratic party proved in recent elections that it is able to temporarily absorb Republican refugees, but many of these voters are “rented,” biding their time and planning to return to a more “normal” GOP should one emerge.

Ironically, many Democrats exaggerated the death of the Republican party in 2008 and 2012, and may be understating it now. Performance in presidential elections—or even in congressional elections—is not necessarily indicative of future success. A minority party can win elections, as Republicans did at the presidential level in 2000 and 2016. Even a collapsing party can win the presidency, as the Whigs did with Zachary Taylor in 1848 and the Democrats did with Buchanan did 1856, only to see his party split in two during his single term.

Reform of our era’s Republican party would require a generational turnover in its leadership, since almost no elected Republicans oppose Trump in the way Sedgwick and Hamilton opposed Adams. Otherwise, there are two possibilities: Democrats can work to accommodate former Republicans in their ranks in hopes of forming a broad enough coalition to swamp the GOP’s Electoral College and Senate advantage. The Democratic party has long been a factious, unwieldy assemblage of interest groups, so there’s reason to believe it could accommodate yet one more. But an electoral coalition stretching from Alexandria Ocasio-Cortez to Liz Cheney may prove too unwieldy to maintain without opposition to Trump binding it together. In 2020, Joe Biden was uniquely suited to unify the anti-Trump coalition. That challenge is now up to Kamala Harris.

The other option is that a new party will eventually fill the vacuum left on the center-right by the MAGAfied GOP, probably pulling some moderate Democrats along with it. Three-party politics are a lot more complicated than two-party politics, as demonstrated by H. Ross Perot’s 1992 presidential campaign and, for that matter, Robert F. Kennedy Jr.’s current bid. If Democrats want to help the Republican party reduce itself to a regional rump, they will need to convince the voters whom Transportation Secretary Pete Buttigieg calls “future former Republicans” to abandon their partisan identity and join a new coalition. It won’t be easy. But when the future of democracy relies on denying MAGA Republicans power, it’s less of a far-fetched option than anyone would have supposed in the pre-Trump era.