Roll of the Dice: Will November Deliver a Trifecta or Divided Government?

A look at four scenarios for this November's elections.

(Composite by Getty Images)

As Americans begin tuning into the presidential campaign in the weeks and months ahead, they’re bound to hear both leading candidates make promises about what they’ll do if they win another term. Some of these promises stand a good chance of being enacted—presidents have broad leeway to exercise control of the executive branch and push policy changes on their own. But much of any presidential agenda typically requires assistance and approval from Congress, making the results of congressional elections just as interesting as who wins the presidency.

While we don’t yet have a clear picture of how House and Senate elections will shake out this November, we know that both chambers are in play. The Democrats, who face a historically difficult Senate map, currently hold a two-seat margin (51–49). We can be reasonably confident that they will lose at least one seat, as Republicans are heavily favored to flip outgoing West Virginia Democrat Joe Manchin’s seat. This would bring the Senate’s partisan split to 50–50. Beyond that, election handicappers consider eight additional Democratic seats competitive to varying degrees versus just two Republicans seats.

On the other side of Capitol Hill, Republicans will be looking to protect their recently acquired House majority, which has grown smaller—historically small, in fact—since the 2022 midterms thanks to the early departure of several members. As of this writing, the GOP controlled 218 seats to the Democrats’ 213. Both parties are defending more than enough potentially competitive seats that the House majority could shift in either direction this November.

Given these narrow margins, control of Congress may turn on just a few hundred thousand votes (or even fewer) smattered across a handful of states, leaving us with several possible outcomes for this November. This includes everything from a Democratic trifecta to a Republican trifecta. Thus, it’s worth looking at how likely each of these possibilities is—and what it could mean for either party’s ability to pass their policy agendas.

Republican Trifecta

One of the more probable outcomes is complete Republican control of the federal government. In this scenario, Trump wins the presidency, Republicans retain their House majority, and they flip at least one Senate seat (which would bring the chamber to a 50–50 split and allow Trump’s vice president to cast tie-breaking votes). This is clearly the best possible result for the GOP. It would allow Trump and his allies in Congress to eye several controversial policies for which he has previously expressed support, including a national abortion ban, another round of corporate tax cuts, and yet another attempt to repeal the Affordable Care Act.

Narrow wins in one or both chambers could conceivably make it more difficult for Trump to get core pieces of his legislative agenda passed. However, there is reason to think that if he wins, he’ll pad Republicans’ ranks to give him some cushion. This is because as American politics and society have become more polarized in recent years, voters have also been less likely to split their tickets—to vote for the president of one party and a member of Congress from the other.

For example, across the last two presidential elections, only once did voters deliver a dual result: when Mainers in 2020 voted for Joe Biden while re-electing Republican Senator Susan Collins.¹ The same trend has played out in the House. Following the 2022 midterms, there are now just 22 “crossover” House districts—or districts where the incumbent is of a different party than the president who carried it in 2020. Compare this to only a few decades ago, when there were over 100 such districts following the 1996 presidential election.

This decline in ticket-splitting matters because it means that whichever presidential candidate wins will probably to see their party do well in key congressional races. In the House, Republicans represent 17 Biden districts, and an environment that produces a Trump victory may help them retain most, if not all, of those seats. And beyond the ones they already control, they could also flip competitive seats represented by Democrats (including the five Trump carried in 2020).

Trump also begins with a big leg up in the Senate. In addition to Manchin’s seat, two other Democrats are defending theirs in states Trump won by healthy margins last time: Jon Tester in Montana and Sherrod Brown in Ohio. If ticket-splitting remains at historically low levels, those are two additional seats that Republicans could easily pick up. Moreover, for Trump to win, he’ll have to flip at least a handful of swing states that Biden carried last time, including some where Democrats are defending competitive Senate seats this cycle like Arizona, Michigan, Nevada, Pennsylvania, and Wisconsin. A nightmare scenario for Democrats is if Trump sweeps all those states and voters also back the GOP candidate those Senate contests. This could give Republicans an additional five seats and bring their net gain to a whopping eight pick-ups.

The party’s margins will matter. Though Trump has molded the Republican Party more and more in his image, the Senate GOP remains home to a few members who are either anti-Trump (Lisa Murkowski), up for election in 2026 in a competitive state (Thom Tillis), or both (Susan Collins). And in the House, Biden-district Republicans may still feel pressure not to stray too far from their more moderate constituents. So to get any of his agenda passed, including his preferred cabinet and judicial nominees, Trump likely needs some breathing room in each chamber.

Biden, Democratic Senate, Republican House

In this scenario, the power balance in Congress would remain the same as it is now. Most likely, the only way this result happens is if Biden wins the presidency, for reasons outlined above regarding ticket-splitting trends.² For Democrats to retain their majority, Tester and Brown will also need to attract impressive levels of crossover support from voters who backed Trump, as he is a heavy favorite to win their states. Given the near-certainty that Democrats will lose Manchin’s seat and that they have few true opportunities to go on the offensive, their best case may be for their Senate majority to look it did at the beginning of Biden’s first term: a 50–50 split, with Vice President Kamala Harris casting tie-breaking votes.

The practical effect of this arrangement in Washington is that voters can expect more of what they’ve seen over the past two years—namely, gridlock on most major legislative items. With a working Senate majority, Biden should still be able to get his cabinet and judicial nominees confirmed, but the chances he’ll be able to accomplish much beyond that are slim. Moreover, if Republicans return with a similarly narrow House majority, the GOP’s right-wing faction could feel emboldened to pick more fights with Biden on everything from debt-ceiling brinkmanship to more investigations into him, his administration, and his family.

However, the status quo rarely stays that way for long. Since 2000, voters have only returned the same government to D.C. twice: in 2004 and 2012. Otherwise, each election has seen partisan control of at least one of the presidency, Senate, or House change hands. So, while there is precedent for things staying the same come November, it’s probably wise not to bank on it.

Biden or Trump, Republican Senate, Democratic House

In a historically-rare-but-entirely-plausible scenario, both the Senate and House could flip to the “out” party in the same election. This would be historic for a couple of reasons. First, that result has never happened before.³ What’s more: since at least the 1850s, voters have only once sent the president of one party to Washington while removing his party from its majority in either chamber—this occurred in 1916 when Woodrow Wilson was re-elected but the Democrats lost the House.

This cycle, though, due to Democrats’ historically bad Senate map, it’s very possible they could lose the chamber no matter who wins the presidency. Conversely, on the House side, the GOP is defending more Biden districts (17) than Democrats are Trump districts (5). Democrats only need to net five seats for a majority, one of which they will get following a July 18 special election in a deep-blue New Jersey district, bringing their target to just four seats. They should also be aided by major redistricting wins in states like Alabama, Louisiana, and New York.

For Biden, this vision of divided government would be much less preferable to the above one, as he would almost certainly encounter greater resistance in the Senate to his nominations, including any potential Supreme Court vacancies. But Democrats would obviously take this over the alternative of a Trump presidency with a GOP Senate. Though Democrats could stymie Trump’s legislative agenda in the House, it would be much easier for him to get the cabinet of his choosing with a cooperative Senate. And perhaps even more importantly, he could build on the judicial legacy of his first term, when the Senate confirmed a record number of his nominees to the federal judiciary.⁴

In all, this election outcome is no sure thing—there’s a reason it has never happened before. Still, there are clear paths for Republicans to re-gain control of the Senate and for Democrats to win back the House, regardless of who wins the presidency.

Democratic Trifecta

The final scenario we may see occur is something Democrats can’t bring themselves to dream of right now: restoring the trifecta they enjoyed when Biden first came into office. If he wins, they have a strong chance of retaining all of their toss-up Senate seats in the battleground states, though Tester and Brown would still have to outpace him in their respective states. And as mentioned above, Democrats will face a friendlier House map this cycle—and they’ll likely only need a net gain of four seats to win the chamber back.

Far from becoming a dreaded lame duck immediately at the start of his second term, a trifecta could give Biden a jolt of energy to pursue many of the priorities he was unable to accomplish in his first two years. A major reason is that two of the biggest obstacles to many of those priorities—Senators Joe Manchin and Kyrsten Sinema—will no longer be in the Senate, as both announced their retirements this year. Manchin and Sinema derailed some of Biden’s preferred policies around the minimum wage and Child Tax Credit and were prominent defenders of the Senate’s filibuster, even as it kept the Democrats from passing policies they agreed with such as protections for abortion access.

This may be a difficult scenario to envision, mostly because winning control of any one of these three offices is expected to be hard enough for Democrats this year. But though it may be a tall order, piecing all three of these together for a unified government is clearly not out of the question either.

1. These were the lowest levels since at least 1980.

2. It’s highly improbable that Trump wins, carrying Montana, Ohio, and at least a few states with toss-up Senate races—and that Republicans don’t flip a single Senate seat beyond West Virginia.

3. There have, though, been plenty of elections in American history in which one party gains seats in the Senate while the other party does so in the House, including the two most recent midterm elections.

4. This includes a possible opportunity for him to appoint a fourth justice to the Supreme Court—something no president since Ronald Reagan has achieved.