The impeachment trial of the US president starts today. This is only the third time in history that a sitting president of the United States is impeached, so whatever the outcome or your own standpoint, this is a historic day. This is also something specific for the American political structure based on the USA Constitution signed by the Founding Fathers.
WebEnglish.se suggests that you bring this up in one way or another in your intermediate classes. They will remember this for the rest of their lives.
I am frequently updating the materials in The USA Now as history is happening right in front of our eyes. You can also follow the trials in the Daily News.