Impeachment

Usually, after some hesitation, everyone or almost everyone raises their hand and I promptly challenge them,"prove it to me". Since we do not have membership cards for U.S. citizenship, after thought and discussion, students usually say "I have a birth certificate." Of course they don't really have one with them, putting them at risk in these days of Immigration and Customs Enforcement, ICE, policing the streets, but they mean they can get an official copy somewhere from someone. So my next question to them is "Where is your parents' birth certificate? And when you figure that out, what about your grandparents and great grandparents?"