2025 could see the rarest divided government in U.S. history

It appears more likely than not that the 2024 election could produce the rarest form of divided government in U.S. history.
Forecasts suggest the House and Senate could flip in opposite directions in the same election for the first time ever. If they do — and if Vice President Kamala Harris wins the presidency — it would be the first time since 1890 that a Republican Senate stands alone against a Democratic House and president.
A Republican Senate is a semi-safe bet this election year, according to top election watchers. But it might be the only safe bet.
Recent polling shows control of the House and White House is up in the air. Whether former President Donald Trump would enter a second term with a Republican trifecta — as he did in 2017 — or whether Harris will be forced to negotiate with one or two GOP-led chambers if elected, comes down to a series of coin-toss elections across several states and two dozen congressional districts.
But regardless of the state of divided government in the next presidential administration, Congress will almost certainly still serve as a frustrating, or fortunate, obstacle to Trump’s and Harris’ “day-one” campaign promises.
The Senate will likely flip from Democratic to Republican control in 2025 after four years of Democratic leadership. Models from The Hill and Race to the WH give Republicans a 70% and 58% chance, respectively, of taking Congress’ upper chamber.
The current Democratic majority of 51 seats faces an unfavorable reelection map with 33 contested seats that disproportionately affect vulnerable Democrats in states like Montana and Ohio.
“In the Senate at this point, the Republicans are pretty clear favorites,” said Miles Coleman, the associate editor of the University of Virginia’s election forecaster, Sabato’s Crystal Ball. “The House is harder to game out.”
The House, where Republicans currently hold a three-person majority of 220 seats, is considered up-for-grabs by most forecasters. Race to the WH gives Democrats a 64% chance of taking the chamber, while The Hill gives Republicans a 54% chance.
But with the added partisan pressures of a presidential election year, party control in the House may come down to 18 first-term GOP representatives in districts that voted for President Joe Biden in places like California and New York. The nationalization of House races could mean these seats, and the control of the House, could go the way of the presidency.
“We’ve been going through this realignment where there are fewer and fewer people who are willing to split their tickets,” Coleman said. “That idea of ticket-splitting starts to really diminish during the Trump era.”
An average of current polling places Trump ahead of Harris in four of the seven battleground states that will likely decide who wins the presidency. Based on these results, if the election were held today, Trump would win the 2024 election with 281 to Harris’ 257 Electoral College votes, according to Real Clear Politics.
Democrats who hope their congressional candidates can ride Harris’ coattails to victory and flip the House are looking for Harris to lead by at least 3 or 4 percentage points in national polls. Harris leads Trump by between 2 to 4 percentage points in most national polls.
A consensus of election forecasts — which combine national and state polling averages with demographic and economic data — tend to narrowly favor Harris. FiveThirtyEight, The Economist, Race to the WH and The Hill all give Harris a 55%-60% chance of victory in November.
If a divided government does emerge from the 2024 election, or even if it doesn’t, the country’s next president will likely have difficulty pushing their agenda through Congress — and that’s a feature, not a bug, of the system, according to Dr. Tristan Hightower, an assistant professor of political science at Bryant University.
“When somebody comes into office, regardless of what they promised on the campaign trail, they face a steep hurdle with Congress, whether they’ve got them on their side or not,” Hightower said.
The Constitution intentionally constructs a “relatively inefficient” legislative branch, Hightower said, both to prevent the chief executive from acting like a “monarch” and to preclude “massive swings of policy” between administrations.
The founders’ structure of checks and balances has ensured that 235 years later, Congress still passes most pieces of legislation in a bipartisan matter, and presidents still face opposition even when their party has complete control of the nation’s governing bodies, according to Hightower, who points to the unified Republican government under Trump from 2017 to 2019 as evidence.
Both Trump and Harris have made promises on the campaign trail that, if constitutional, would likely require 218 votes in the House and 60 votes in the Senate to become law. Trump has promised to initiate the largest deportation of illegal immigrants in U.S. history. Besides facing the constitutional question of local police enforcing federal immigration policy, the massive undertaking would likely run into the same funding problems Trump faced with construction of the border wall during his first term.
Harris, on the other hand, has proposed an economic agenda that includes subsidizing first-time homebuyers, implementing rent controls and banning grocery “price gouging.” She also supports making the standard of abortion access previously established by Roe v. Wade the law of the land. To achieve these goals, Harris has said she would support eliminating the Senate filibuster, an important instrument of bipartisanship that requires 60 votes for most legislation to pass.
Hightower, for his part, doesn’t buy the apocalyptic language being used by partisans to describe the effects on the country of either a Trump or a Harris presidency. “If we look at the data,” Hightower said, Congress has continued to function as a check on the president’s power, despite its bad reputation.
“I do believe, based on the evidence, in the stickiness of our institutions, the resilience of our institutions,” Hightower said. “So I am, perhaps, always cautious of these ideas of populist takeovers.”