Mark J. Westpfahl didn’t wait until this week to teach his students about impeachment procedures. He didn’t wait until the congressional gavel fell on public hearings into President Trump’s behavior dealing with Ukraine’s leader.

In September, when the private phase of the process began, Westpfahl postponed regularly scheduled lessons in his history class and used the historic moment to teach students about impeachment. The educator at Capitol Hill Gifted and Talented Magnet School in St. Paul, Minn., spent several days talking with his middle school students about the process — something that is now being repeated in thousands of classrooms across the country.

Topics include the Constitution, the impeachment process and the different roles played by the House and Senate, the separation of powers and the presidents who have been impeached (Bill Clinton and Andrew Johnson) and those who came close (Richard Nixon). In some classes, students participate in mock impeachment trials, arguing both sides and deciding Trump’s fate.

Lesson plans and tips for teaching impeachment are starting to flood the Internet, including this one from the iCivics website.

“All too often, we look at history as these singular events that happened long ago. We sometimes try to connect many of those events to the present, but we fail to realize sometimes that the events that are unfolding around us every day are historic, too,” Westpfahl said. “They are shaping our present and our future, and they almost always have some connection to events that happened in the recent past or have deeper roots further in the past.”