The Oval Office meeting between Elvis Presley and President Richard Nixon was one of the original pics-or-it-didn't happen moments — and there were, indeed, pics. In fact, a photo of Elvis and Nixon shaking hands is the most requested image in the National Archives.

Elvis & Nixon, a movie that opens in theaters today, reenacts that meeting — with Kevin Spacey in the role of Nixon and Michael Shannon as Elvis. Director Liza Johnson's feature faces an uphill battle for pop-culture claim on best-known contemporary retelling of the story, competing with a cherished Drunk History episode starring Bob Odenkirk and Jack Black.

After seeing a preview screening of the new movie, I cracked my copy of Peter Guralnick's Careless Love to check the details as shown in the movie. In broad strokes, the film is accurate: yes, Elvis Presley paid a semi-spontaneous visit to the White House on Dec. 21, 1970, having invited himself via a letter handwritten during the flight to Washington. Yes, he asked Nixon to make him an licensed agent of the federal Bureau of Narcotics and Dangerous Drugs — and yes, Nixon agreed. Yes, Elvis brought a gun — a gun, a chrome-plated Colt of WWII vintage — as a present for the President. That all happened.

Working from a script by Joey Sagal, Hanala Sagal, and Cary Elwes (yes, that Cary Elwes), Johnson's made a competent and often entertaining film that doesn't complicate the truth with a lot of unnecessary embellishments — or, for that matter, any that might have actually been helpful. Elvis & Nixon shows, in a broadly accurate way, how the bizarre meeting happened. Where it fails is at explaining exactly why the meeting happened. Who was Elvis in 1970, and why did he so yearn to get that badge from the president?

There's no concise answer to that question, nor is it easy to explain how Elvis could so sincerely crusade against what he saw as a plague of drug culture among young Americans while sliding, himself, into a range of drug habits that would ultimately claim his life. A photo that's briefly glimpsed in Elvis & Nixon shows the King proudly displaying his Shelby County deputy's badge along with his posse, all of whom have deputy badges too. Right next to Elvis, flashing his own badge, is none other than Dr. George Nichopoulos: the infamous "Dr. Nick" who was all too willing to load his patient up on dangerously addictive prescription drugs.

Even if it's not easy to explain how Elvis justified his seemingly contradictory positions on drugs, there's a lot the film could have dug into. There's the youth rebellion that left Elvis, once its leader, in the dust (the fact that Nixon felt the need to court the approval of the once-relevant Presley was a bellwether of the president's dismal status among young Americans); there's the peculiar world of celebrity at its most precipitous heights; there's Elvis's manipulative romantic behavior, which included taking the virginity of a House Armed Services Committee staffer on the very night after his visit with Nixon.

All of that is glossed quickly over in Elvis & Nixon, which instead spends time developing the relationship between Elvis and his longtime friend Jerry Schilling — who accompanied Elvis to the White House, and who the film suggests Elvis valued because he knew "the boy from Memphis" hiding behind the shades and the chains.

Okay, fine, but the rags-to-riches story of "the boy from Memphis" is so much less interesting than the story of the man from Memphis who Elvis Presley had become in 1970. The screenplay's suggestion that Elvis was merely giving the people what they wanted misses the point. In fact, the 1970s Elvis was trying to give the people what he wanted to be: an accomplished actor, a respected agent of law and order, and a supreme showman. Well, one out of three ain't bad.

If "the people" wanted anything, it was the young and dangerous Elvis they remembered from their youth, not the bloated and bedazzled King with an orchestra blasting Strauss. It's testament to Elvis's vast charisma that he managed to reinvent himself even through a drug-addled haze, giving us an "old Elvis" who became so iconic that when the Postal Service decided to create an Elvis stamp, they had such a hard time deciding between the two they had to put it to a popular vote.

Really understanding what Elvis was striving for with that technically legal but otherwise farcical drug-agent badge would require delving into that thorny territory — but Elvis & Nixon is only interested in the shallow spectacle of Elvis marching into the White House toting a commemorative handgun. Shannon's Presley remains a mumbling cipher, low-energy and opaque.

By contrast, the supporting actors — including Johnny Knoxville as Elvis's friend Sonny and a sultry Sky Ferreira as Jerry's girlfriend back home — enliven the proceedings. Nixon turns out to be the real star of this show, thanks in large part to an amusingly deadpan performance by Spacey, who has a lot of fun with Tricky Dick's struggle for dignity in trying circumstances. (His last line in the film is, however, an offensive attempt by the screenwriters to play the situation in Syria for a quick laugh. Nixon sure didn't see that genocide coming, ho ho ho.)

Elvis & Nixon might be enjoyable as a nostalgia trip for those who remember 1970, and might fill in some of the gaps for those who don't, but it brings us no closer to understanding what was really behind that strange summit in the winter of our discontent.