A spectre of inevitability hangs over New Orleans in the final run-up to America’s high holy day. The Kansas City Chiefs, having spent the past half-decade as the National Football League’s most dominant force, are on the verge of something never before seen: a third successive Super Bowl title.

Theirs is a kind of supremacy that feels almost unnatural in the modern NFL, an era defined by salary caps and roster churn and parity-by-design, where success is intended to be fleeting in the best interests of the revenue-sharing collective. Yet here they are again, winners of 17 games so far and one more from a three-peat no team in the six-decade Super Bowl era has even come within 60 minutes of accomplishing.

Related: Patrick Mahomes, the Super Bowl’s final boss who evolved towards greatness

Standing in their way are a team they know well. The Philadelphia Eagles, with 17 wins of their own, are back in the Super Bowl for the second time in three seasons, still nursing the scars of their first meeting with Kansas City. That game ended in heartbreak: a heart-stopping 38-35 Chiefs win in which a hobbled Patrick Mahomes orchestrated a near-perfect second half to overturn a 10-point deficit.

It was the first Super Bowl in which both teams scored at least 35 points, and a rematch so soon after – the ninth in Super Bowl history – only lends to the gravity of the occasion. The Eagles have spent much of the past year trying to convince themselves and their rabid supporters they are built to go the distance after last year’s spectacular late-season collapse raised doubts about whether they are the ascendant power they once seemed. The Chiefs, on the other hand, have long since arrived and have given no signal they are ready to exit the stage.

New Orleans, hosting a joint-record 11th Super Bowl but for the first time since 2013, remains a fitting stage for football’s annual bacchanal of conspicuous consumption. The Superdome has long been a site of NFL mythology, the backdrop to Joe Montana’s legendary game-winning drive in Super Bowl XXIII, Tom Brady’s first ring in Super Bowl XXXVI, and the surreal 34-minute blackout that nearly derailed the Baltimore Ravens’ title run a dozen years ago.

Even a French Quarter that has come to resemble a demilitarized zone in the weeks after the New Year’s Day terror attack has done little to dampen the visiting fans’ enthusiasm. This is particularly felt on Bourbon Street, where bag searches of pedestrians entering the area started on Wednesday and national guardsmen armed to the hilt patrol barricades at every entryway, a heightened security presence that makes the Paris Olympics seem like a county fair.

There is also no shortage of personal stakes. Andy Reid, coaching in his fifth Super Bowl, will break Bill Belichick’s record for most postseason games coached (45) and, with a win, join a select group of head coaches with four or more Super Bowl victories. For Mahomes, already a three-time Super Bowl most valuable player at 29, a win would move him into a category all his own: no quarterback has ever started five Super Bowls before turning 30, and none have won four before reaching that milestone. He has thrown 43 postseason touchdown passes, three shy of surpassing Joe Montana and Aaron Rodgers for second-most all-time.

The Eagles, meanwhile, are fighting to assert their own legacy. Their stormy head coach, Nick Sirianni, only 43, is making his second Super Bowl appearance in his first four seasons, a feat previously accomplished only by Joe Gibbs and Mike Tomlin. Jalen Hurts, due to become the eighth quarterback to start multiple Super Bowls in his first five seasons, returns to the biggest stage with unfinished business. The 26-year-old played arguably the best game of his career against Kansas City two years ago, setting Super Bowl records for scrambling (70 rushing yards) and rushing touchdowns by a quarterback (three), and this time he has a new weapon alongside him: Saquon Barkley, the league’s leading rusher amid perhaps the best ever season by an NFL running back.

Barkley’s presence has transformed Philadelphia’s offense into a bruising, old-school machine, one that has produced 39 rushing touchdowns this season – including many by Tush Push, the trademark short-yardage play that has been parsed by Neil deGrasse Tyson and hailed as unstoppable. Barkley, who turns 28 on Sunday, himself has rushed for 442 yards in the postseason, putting him within reach of John Riggins’s record for most rushing yards in a single playoff run. If he gets to 500, he will join Terrell Davis and Riggins as only the third player to do so.

Of course it wouldn’t be the Super Bowl without an excess off-field spectacle, and coming off an election year, the presence of Donald Trump at the game is sure to add a layer of political theatre. America’s once and restored king has long co-opted sports as not merely a proxy battle in the culture wars but the primary spectacle, and while his appearance will be largely symbolic in a city only 90 miles from the freshly rebranded Gulf of America, the response to him – cheers or boos – will inevitably become a talking point. It is an unwelcome distraction for the NFL, which prefers to focus on safer narratives: the enduring greatness of Mahomes, the redemption arc of the Eagles, or even the sheer absurdity of ticket prices, which soared past $8,000 (£6,500) on the resale market earlier in the week.

For those watching at home, the Super Bowl remains a breathless collision of sport, commerce and entertainment. The game will probably draw more than 120 million viewers, many of whom will be just as invested in the half-time show – Kendrick Lamar will headline, to the quiet chagrin of hometown snub Lil Wayne and a certain down-bad Canadian – as they are in the result. Advertisers have again paid upwards of $8m for 30-second spots, competing for attention in an age when social media can either amplify or bury their efforts within minutes.

Somewhere beneath it all is the actual game, which promises to be compelling. The Chiefs’ defense, once an afterthought, has been their backbone this season, their secondary capable of shutting down even the best quarterbacks. The Eagles, meanwhile, have thrived behind a defense that has been completely reinvented under Vic Fangio. The first Philadelphia team to rank No 1 in total defense since Bud Carson’s epochal 1991 unit, they are young and fast and athletic at all three levels with a chemistry and togetherness that seem to be improving by the week. The rookie linebacker Nolan Smith has been a revelation in the playoffs, recording a sack in every postseason game so far – if he does so again on Sunday, he will be the first player to register a sack in four separate games in one postseason.

Related: Chiefs v Eagles Super Bowl questions: when’s kickoff? Who is the halftime performer? Are Taylor and Trump going?

Then there is Travis Kelce, Mahomes’ most trusted weapon. With 174 postseason catches, he already owns the record for playoff receptions, and a highly unlikely 207 yards against the Eagles would see him break Jerry Rice’s postseason record for total receiving yards. Another solid performance on Sunday could see him break Rice’s Super Bowl receptions mark (33) too. Keeping Kelce contained will be at the top of Fangio’s priorities.

Should Kansas City win, the conversation around these Chiefs will shift permanently from great to historic. They have already appeared in five of the past six Super Bowls and are only the fourth team ever to make three straight appearances. The others – the 90s Bills, the early 70s Dolphins and the 2016-18 Patriots – all fell short of winning three on the trot. Mahomes and Reid have a chance to achieve what even Brady and Belichick could not.

If Philadelphia buck the odds – they’ll go off as slim one-and-a-half-point underdogs –, it will not only mark their second Super Bowl title but a full-circle moment avenging their loss from two years ago and breaking Kansas City’s stranglehold. In a season when they looked vulnerable, then dominant, then vulnerable again, nothing would be more fitting than ending it on top.

Repeat or revenge? Whatever happens, history will be made. Either Kansas City will cement themselves as the greatest dynasty of the modern era, or Philadelphia will thwart their bid for football immortality at the final hurdle. Either way, by the time the confetti falls in New Orleans, the NFL will have a new standard for what greatness looks like.