It was a great moment in chair history.

Clint Eastwood's rambling, off-color interview with an empty chair Thursday night in prime time at the Republican National Convention joins Indiana basketball coach Bobby Knight's chair toss, Jennifer Beals' soaking wet chair dance in "Flashdance" and George Strait's 1985 chart topper "The Chair."

If online chatter is any indication, the legendary actor's peculiar endorsement of Republican presidential candidate Mitt Romney almost certainly overshadowed the convention's main event -- Romney's acceptance speech -- in water cooler talk Friday morning.

"Eastwooding" -- posing (as if to harangue) with an empty chair -- is now part of the vernacular and a craze on social media.

Almost 80,000 tweets were posted during Eastwood's appearance, according to the website Knowyourmeme.com.

ABC News reported that the Twitter account @InvisibleObama (its profile picture is an empty chair) had 20,000 followers within 45 minutes of being created.

Knowyourmeme.com credits Salt Lake Tribune political reporter Robert Gehrke with creating the #Eastwooding hashtag. Within an hour, it had generated 7,100 related tweets, many with photos of people and even pets scolding empty chairs.

Eastwood's ploy, while unusual, was not unprecedented.

Smithsonian magazine blogger Colin Schultz unearthed a contemporary account of vice presidential candidate Burton Wheeler using an empty chair as a prop to grill an absent President Calvin Coolidge.

More recently, CNN talk show host Piers Morgan confronted an empty chair when U.S. Rep. Todd Akin cancelled an appearance on his show.

Jim Hoberman, who was senior film critic at the Village Voice for more than 20 years, closely follows the intersection of politics and the movies. He says Eastwood's ad-libbed performance damaged his "Mount Rushmore quality."

The actor, a longtime Republican, was the convention's "great attention magnet," Hoberman said.

He may have attracted too much attention.

"In some respects, (Romney) was upstaged by this, and that can't be good," he said. "It's not even that he was partisan. He was partisan in a particularly kind of clueless and tasteless way. That will damage (Eastwood's) reputation, and it doesn't help Romney. It was an unnecessary distraction."

The White House has taken note.

President Barack Obama's official Twitter account responded to Eastwood and the RNC a little after midnight with a photo of Obama seated in the president's chair. It was accompanied by a message: "This seat's taken."

In other words, to paraphrase Strait, that chair onstage at the convention wasn't Obama's chair after all.

Rene Guzman contributed to this report.