The more straightforward reading, however, is that the Senate has no business convicting Trump so long as Americans remain evenly split on his impeachment and removal—as indicated by a Washington Post/ABC News poll in November, a Wall Street Journal/NBC News poll in December, and a NPR/PBS NewsHour/Marist poll earlier this month. And that position finds no support in the Constitution. House Majority Leader Steny Hoyer got it right, constitutionally speaking, as the House’s public hearings got under way back in November: “This is not a question about polls, this is a question about each member deciding about whether or not they believe conduct that clearly has been corroborated by many, many witnesses rises to high crimes and misdemeanors.” 

In short, popularity is how presidents get elected (Electoral College distortions aside), but unpopularity is not a legitimate basis for their removal. The Constitution provides that a president may not be impeached and convicted except for in cases of “Treason, Bribery, or other high Crimes and Misdemeanors.” This is a legal standard, albeit one whose application the Constitution entrusts to a political branch rather than to the courts. Denying the essentially juridical character of an impeachment trial tends to take the focus off the Senate’s obligation to vote in accordance with its good-faith interpretation of the evidence and the Constitution. It puts the spotlight on national opinion and threatens to legitimize voting in accordance with political expediency.