How have past impeachment efforts influenced midterm outcomes and public opinion in comparable moments?
Executive summary
Impeachment efforts have had uneven effects on midterm outcomes and public opinion: in some cases they energized opposition voters and punished the president’s party, while in others—most notably Bill Clinton’s 1998 impeachment—they produced a backlash that helped the president’s party hold or even gain seats [1] [2]. The political context—presidential approval, media polarization, party control of Congress, and whether the public views the proceedings as legitimate—consistently mediates electoral and opinion effects [3] [4].
1. Historic patterns: rare but consequential when aligned with broader forces
Historically, impeachment is uncommon, and its electoral effects track larger political forces rather than operating in isolation; the aborted move against John Tyler cooled when the Whigs lost the midterms, showing impeachment’s dependence on partisan fortunes [5]. The 19th-century spectacle around Andrew Johnson illustrates that impeachment can be part of a wider struggle that reshapes public opinion and midterm outcomes when tied to mass political mobilization, such as Johnson’s “Swing Around the Circle” campaign that sought voter support ahead of midterms [6].
2. The Clinton exception: public sympathy and a midterm backlash against the initiators
The most often-cited modern example is Clinton’s 1998 impeachment, where public opinion largely favored Clinton and voters punished the Republican initiators in that midterm cycle: Democrats gained seats in the House and the Senate balance remained unchanged, an unusual anti-presidential-party deviation attributed to public rejection of the process as excessive [1] [2]. Analysts such as Ron Brownstein found that members who voted to impeach paid at most a modest price in subsequent elections, but aggregate results showed the party advancing rather than losing ground in 1998, demonstrating that impeachment can backfire when the public perceives it as partisan overreach [3] [2].
3. Watergate and Nixon: criminal exposure, resignations and political realignment
When impeachment is closely connected to clear criminal exposure and wide media consensus—as with Nixon and Watergate—effects on public opinion and subsequent elections can be decisive; Nixon resigned before a full House vote amid collapsing political support, and the episode reshaped trust in institutions and electoral rhetoric for years afterward [7]. That episode underscores that legitimacy and evidentiary clarity amplify impeachment’s political weight in the public’s eyes [7].
4. Trump’s impeachments and contemporary polarization: muted electoral effects in a polarized era
The two impeachments of Donald Trump in 2019–2021 produced limited immediate electoral consequences at the congressional level because Senate acquittals and polarized media ecosystems hardened partisan views, blunting the capacity of impeachment to change swing voters’ opinions [8] [9]. Scholars and commentators have argued that increasingly partisan media and narrow partisan margins in Congress have turned impeachment into a partisan weapon more than a unifying corrective, reducing its midterm leverage when the public is already polarized [10] [11].
5. Institutional norms, frequency and democratic costs
Recent upticks in impeachment use—multiple impeachments in a short span and moves against cabinet officials—have raised warnings that frequent partisan impeachment threatens norms and can desensitize voters, diluting future political effect and potentially incentivizing tit-for-tat cycles rather than accountability [4] [12]. Bipartisan policy analysts and constitutional historians caution that when impeachment becomes routine, its signaling power to voters weakens and its use reflects party insecurity as much as principled oversight [10] [4].
6. What actually shifts votes: legitimacy, timing and the electorate’s focus
Across cases, three indicators consistently predict whether impeachment will influence midterms and public opinion: the public’s view of the process’s legitimacy and the clarity of wrongdoing; the president’s approval and issue salience (economic conditions often dominate); and the timing relative to elections—late-breaking inquiries may fail to move entrenched views while sustained revelations combined with bipartisan consensus are likelier to reshape swing voters’ behavior [3] [7] [8]. When those conditions are absent, impeachment tends to harden partisan attitudes rather than produce broad electoral realignment [3] [11].