Notwithstanding the Mueller ­investigation’s conclusion that President Donald Trump did not conspire with Russia to win the 2016 election, many Democrats have not given up on impeachment. Advocates for impeachment point to the publicly available proof of Trump’s misdeeds—the potential obstruction of justice flagged by Mueller, of course, as well as the evidence uncovered by the federal and state campaign finance and tax investigations in New York—and argue that the House must impeach Trump, even if the possibility of conviction in the Senate is remote.

But Speaker of the House Nancy Pelosi will not be deterred. She continues to maintain that, while investigations will continue, impeachment is off the table. This is a defensible position: contrary to the view of many impeachment proponents, the Constitution does not clearly mandate that the House begin impeachment proceedings. While Article I provides the House with “the sole power of impeachment” and Article II states that impeachment is warranted for “Treason, Bribery, or other high Crimes and Misdemeanors,” the framers did not define “high crimes or misdemeanors”—or indicate whether impeachment should be mandatory when the House is faced with evidence of impeachable conduct.