LOS ANGELES  Hollywood and older Americans have never had much use for each other. The 50-plus crowd doesn’t go to opening weekends or buy popcorn; a youth-obsessed Hollywood has happily ignored them.

But in the last few months an older audience has made a startling reassertion of its multiplex power. “True Grit,” “The King’s Speech,” “The Fighter,” “Black Swan”  all movies in contention for a clutch of Oscars on Sunday  have all been surprise hits at the box office.

And they have all been powered by people for whom 3-D means wearing glasses over glasses, and “Twilight” sounds vaguely threatening.

Hollywood, slower than almost any other industry to market to baby boomers, may be getting a glimpse of its graying future. While the percentage of moviegoers in the older population remains relatively small, the actual number of older moviegoers is growing explosively  up 67 percent since 1995, according to GfK MRI, a media research firm.