“Dismantling the Party System” was an article long in the making, but the event that compelled us to sit down and write it was Donald Trump’s second impeachment in January 2021. A common refrain among politicians and media outlets in the wake of Trump’s trial was that his impeachment was the “most bipartisan in history.” This statement is awkward in many ways—after all, this is a history that includes only three other presidential indictments, one of which was the first Trump impeachment in 2019. But we found comparisons with Andrew Johnson’s 1868 impeachment particularly frustrating.
There was nothing simple about the partisan politics of that 1868 impeachment. Andrew Johnson was elected vice president on the Union Party ticket in 1864. Abraham Lincoln had formed the Union Party during the Civil War in an effort to expand the base of the Republican Party—importantly, the two labels were not interchangeable. By 1868, the Union Party had mostly dissolved on the national level while maintaining some salience in state and local contests. Many, though not all, of the congressmen who ran as Union Party men during the Civil War ran as Republicans in 1867. As a result, Johnson was impeached by a House controlled by the majority Republican Party, with all Democrats in opposition or not voting.
How, then, are we to understand the partisan breakdown of the 1868 vote to impeach? If we conflate the Union Party with the Republican Party, was Johnson a Republican? He may have flirted with the Democrats in pursuing a revived Union Party, but he was not a Democrat. And while Democrats certainly supported Johnson’s vision for Reconstruction over that of the Republicans, they did not view him as a member of their party either. In other words, including Johnson in any kind of accounting of the partisan politics of impeachments is confusing at best.
The problem with this story—and the story of so many other political battles in the nineteenth century—is that our twenty-first-century politics do not map neatly onto that era. At the same time, even our scholarly tools could not offer a clear way to explain the partisan context for Johnson’s impeachment. For more than half a century, historians have relied (often implicitly) on a model of organizing U.S. political history around distinct and separate “party systems,” pitting two competitive, stable, national parties against one another for long stretches of time between short bursts of realignment. In the context of the shifting political landscape of 1868, however, explaining the partisan politics of the Johnson impeachment through the party system model is the equivalent of forcing a square peg into a round hole.