By Sarah Rodman
Constitution USA With Peter Sagal 7 p.m., WGBH Channel 2
This fascinating four-part series, hosted by NPR’s Peter Sagal of “Wait, Wait . . . Don’t Tell Me!” fame, is framed around a cross-country Harley ride in which he explores the relevance of the Constitution in modern America on everyday Americans. “The whole point of the series, and the whole reason I was excited to do it is because we really wanted to take civics out of the classroom,” Sagal said, when meeting with TV reporters at the Television Critics Association press tour earlier this year. “And the way that we wanted to do it was, in addition to the experts who provide context and history, we wanted to talk to people who are genuinely and truly affected by the Constitution.” The issues addressed will include federal power vs. states’ rights, privacy, medical marijuana, and gun control. Sagal joked that between “Wait, Wait,” “Constitution,” and his Harley, he was a “badass nerd.”
Family Tree 10:30 p.m., HBO
Christopher Guest (“Best in Show,” “A Mighty Wind”) brings his unique comedic touch — and regular repertory of funny folks like Fred Willard and Michael McKean — to this new series starring Chris O’Dowd (“Bridesmaids”) as a man in search of his identity.
Bob’s Burgers 8:30 p.m., Fox
9 p.m., National Geographic
Hanging up the hooks on season 2.
Mad Men 10 p.m., AMC
SCDPCGC? They might need to buy a vowel.