Will “American Sniper’s” gargantuan box office make it a surprise favorite at the Oscars? The Clint Eastwood drama about Navy SEAL Chris Kyle is peaking just days before voters are about to receive their ballots on Feb. 6. Over the long weekend, the Warner Bros. release made an estimated $105.3 million — already more than any of the other best picture nominees.

The Academy is often stubbornly immune to popular sentiment; “Avatar,” after all, lost to “The Hurt Locker” in 2010. And for that reason, I still think “Boyhood” is going to win best picture. It’s the frontrunner that’s picked up nearly every precursor award, and “Sniper” missed out on a crucial directing nomination for Eastwood. Only four films in Academy history (including 2012’s “Argo”) won picture without a director nomination.

But the buzz surrounding “Sniper” could help Bradley Cooper, who landed his third consecutive career acting nomination (after “Silver Linings Playbook” and “American Hustle”). Until now, the best actor race has been a two-man battle between Eddie Redmayne (“The Theory of Everything”) and Michael Keaton (“Birdman”). Yet like Sandra Bullock in “The Blind Side,” the crowd-pleasing nature of Cooper’s portrait of Kyle — a role for which he packed on 40 pounds and learned how to fire sniper rifles — could result in a last-minute surge.

Cooper could also benefit because he’s the most overdue, against four competitors who are all first-time nominees. Of the 20 other actors who have ever received three consecutive (or more) Oscar nominations, 60% won a statue in the first three years. Two of the actors, Marlon Brando (1954’s “On the Waterfront”) and Elizabeth Taylor (1960’s “Butterfield 8”), won their Oscar on their fourth consecutive nomination. The last actor before Cooper to Oscar three-peat was Renee Zellweger (2001’s “Bridget Jones’ Diary,” 2002’s “Chicago,” 2003’s “Cold Mountain”), who won on her third try. It’s hard for voters to keep voting against an actor everybody in Hollywood finds so likeable.

On the downside, Cooper is starring in a Broadway play, “The Elephant Man,” which could limit his campaigning in Los Angeles. One of the most reliable predictors of who will win the best actor Oscar is the SAG Award, for which Cooper isn’t nominated. Since the SAG Awards started in 1994, an actor has never won the Oscar for best actor without a SAG nomination.

In a year where most of the big Oscar races already feel like they are over — Julianne Moore should have her speech ready for “Still Alice” — best actor could be a nail-biter until the envelope is opened on Feb. 22. I still think Redmayne will win, but don’t count out Cooper.