Among the artifacts displayed at the "Gridiron Glory: The Best of the Pro Football Hall of Fame" exhibit opening Saturday at the Minnesota History Center is Knute Rockne's leather helmet from 1919. Nearly a century after he wore it, the well-worn headgear serves as a symbol of pro football's historical hold on sport and society, as well as a reminder of the existential threat that head injuries pose to the world's most popular league.

This hold (a blitz, really) on America was in full force in recent days. Sunday's first-ever regular-season game at the new state-of-the-art stadium in downtown Minneapolis didn't disappoint, as the Vikings-Packers rivalry riveted fans in U.S. Bank Stadium as well as in living rooms and barrooms nationwide. In fact, the broadcast helped sack Sunday's Emmy Awards to their lowest ratings ever.

The Emmys, a celebration of the past season and a launch of the next, honor TV's best. Well, at least qualitatively. Quantitatively, the NFL is usually TV's best, with games and postgames leading Nielsen ratings (18 of the top-20 watched events ever are Super Bowls). In fact, for four months (plus playoffs) the gridiron undergirds not just ESPN but broadcast networks, too — and at an essential time, which is why football is as traditional as turkey on Thanksgiving.

Pigskin's popularity will face a stiffer test than the Emmys on Monday, however, as the first presidential debate in an incredibly compelling election takes place. Still Donald Trump — an aspiring commander in chief who was once a New Jersey Generals owner in the long-defunct USFL — wasn't wrong to fret that football could erode debate ratings the two times the events go head-to-head.

Football is also a bit of a backdrop to the campaign narrative itself, especially with Colin Kaepernick's national-anthem protest over officer-involved shootings prompting polarized responses commensurate with a deeply divided society. (This issue even threatened to relocate Sunday's Vikings game out of Charlotte, the new epicenter of protests, but the game will go on as scheduled.)

The "Gridiron Glory" exhibit reflects how deeply the NFL is ingrained in U.S. society in displays dedicated to league pioneers (and earlier-era teams, including the Duluth Eskimos), equality efforts, great moments, players, teams (alas, the Vikes aren't part of the display on dynasties) and other features. But this societal-sport linkage is especially apparent in the portion showing "football as a way of life," which among other cultural touchstones shows Jim Brown's football-to-film transition and transformational figures such as Howard Cosell.

"The NFL on TV, the marketing, the branding — it has cemented it as not just a pop culture phenomenon but almost a nationwide heritage aspect," said Rachel Knapp, curatorial assistant with the Pro Football Hall of Fame ("I'm from a Steelers family," she added).

"Football is a kind of way that people identify with their states and cities, and has led to a huge industry that is the NFL — and that becomes a system that perpetuates itself," said Prof. Douglas Hartmann, associate chair of the University of Minnesota's Department of Sociology. Hartmann, who teaches a course in sociology and sport, added that the NFL "feeds into idealized visions of American exceptionalism and nationalism, and American identity."

Of course, other societies have unbreakable bonds with other sports: cricket in India and Pakistan; rugby in New Zealand and South Africa; soccer in Great Britain and, well, just about everywhere else football features goals, not touchdowns. These ingrained, intertwined links reflect universal values of sport. "There are few social forces in our modern world that create this kind of community," Hartmann said.

These social forces, let alone the marketing ones, suggest that the NFL will endure despite its challenges. But because it's unconscionable that concussions continue to erode players' lives, changes — be it in equipment or rules reformation, or both — must occur, just as they did around Rockne's era. "I think it's a very real set of problems about concussions, health and safety, and potentially a very expensive one," Hartmann said. "But I don't think it's going to be the elimination of football — there is just too much involved, too much passion, too much money, and too many people still playing it."

And hopefully they'll soon play it in head gear that so revolutionizes safety that it ends up in a museum exhibit just like Rockne's leather helmet.

John Rash is a Star Tribune editorial writer and columnist. The Rash Report can be heard at 8:20 a.m. Fridays on WCCO Radio, 830-AM. On Twitter: @rashreport.