For a monthlong PBS series, Sagal traveled cross-country to illuminate the original document and its 27 amendments that define America. "Constitution USA" debuts Tuesday (check local listings for times).
While most people think they know more about the Constitution than they do, Sagal said, they all share a firm belief in it.
"They may not understand its specifics. They may not know that the word `freedom' does not appear in the body of the Constitution, it only appears in the First Amendment," he said, which includes protections for religion, speech and the press.
"But they do know that in this country we have a rule of law and nobody is above the rule of law, and they do know there are limits on what the government can do."
Sagal, whose weekly NPR comedy news quiz is based in Chicago, was approached for the series by Insignia Films, its producer with a division of Twin Cities Public Television, the PBS affiliate for Minneapolis-St. Paul.
For Sagal, it was a chance to learn more about the Constitution and to relearn how to handle a motorcycle. A self-described "biker reborn," he rode a red, white and blue Harley-Davidson across 26 states during 50 days of shooting last summer. There was a side trip to Iceland, which Sagal said "crowd sourced" a new constitution after the financial collapse of 2008.
To illustrate how Americans see their Constitution, Sagal talked with people confronting issues including affirmative action, voting rights and same-sex marriage. Animation, graphics and archival footage from TV and movies help explore the document's history and text.
"There is one thing that sets us apart from most other nations in the world and that is our Constitution," retired Supreme Court Justice Sandra Day O'Connor told Sagal. "It serves every American every day. No citizen can be denied due process of law or equal protection under our laws."
The Constitution was the real American Revolution, as one commentator puts it in the series.
"Prior to that, the American Revolution was just a rebellion of colonies against the mother country, which had happened before and happened since," Sagal said.
The TV program provides Sagal, known for his quick wit on radio, with the chance to apply it to a broader canvas.
He said the NPR show requires him to work in "a very limited form of expression, which is sort of like humor haiku: I can talk about anything I want as long as I can do it in two minutes and four jokes."
"I was very excited at the opportunity to talk about more serious things at greater length, while still being funny - I hope."
Lynn Elber can be reached at lelber(at)ap.org and on Twitter (at)lynnelber.