Beginning in January 2025, Republicans in Washington will achieve what's commonly known as a governing "trifecta": control over the executive branch via the president, combined with majorities for their party in both the House and the Senate. You might think that a trifecta, which is also referred to as "unified government" by political scientists, is a clear recipe for legislative success. In theory, when political parties have unified control over the House, the Senate and the presidency, there should be less conflict between them.

Because these politicians are part of the same political party and have the same broad goals, it seems like they should be able to get their agenda approved, and the opposing minority party can do little to stop them. But not all trifectas are created equal, and not all are dominant. Researchshows that political gridlock can still happen even under a unified government for reasons that are likely to be on full display when Republicans assume leadership of Congress and the presidency.

Majority size matters A unified government will make President Donald Trump's ability to enact his agenda much easier than if, for example, Democrats controlled the U.S. House, as they did during the second half of his first term, from 2021-2022.

But tight margins in both congressional chambers mean that, even with a trifecta, it won't be a cakewalk. Trump will be the sixth consecutive president with a trifecta on Day 1 of his presidency. But history – and simple m.