Empty chairs are hardly original in politics, though they're not always used in such a formal situation to illustrate such a somber point.
The most common referral to empty chairs springs up each campaign cycle, when the number of backsides in chairs is used by the media to illustrate candidates' strengths and weaknesses. "Empty seats haunt Obama" was the headline in Politico in May 2012. This cycle, Donald Trump took offense to a September New York Times report that suggested one of his rallies had empty seats. "Perhaps conscious of the empty seats in the back of the room, he repeatedly commented on the size of the audience and said he had added the event to his schedule with little notice," the Times's Jonathan Martin reported.
And the empty podium shown at a recent ABC News debate while Hillary Clinton was late returning to the stage wasn't optimal imagery for her campaign.
Perhaps the most famous empty chair in recent political history is the one that sat on stage next to Clint Eastwood at the 2012 Republican National Convention. In a rambling, widely panned 12-minute speech, the actor pretended the chair was Obama, sometimes implying the president had offered obscenities. "What do you want me to tell Romney? I can't tell him to do that -- he can't do that to himself." The event even has its own Wikipedia page.
At the time, much of the political world thought Eastwood's empty chair stunt was pretty bizarre. But what Eastwood did has roots in American politics going back at least to 1924, said Bill Gaston, a senior fellow with the Brookings Institution.
"This is a frequently used device to symbolize either the unwillingness of a candidate to debate or some other fact about the candidate," Gaston said.
In 1924, Progressive vice presidential nominee Burton K. Wheeler used an empty chair to symbolize what he said was a voiceless President Calvin Coolidge. Colin Schultz with Smithsonian Magazine dug up Wheeler's autobiography in 2012 to detail the chair incident.
Apparently Wheeler was campaigning in Des Moines (some things never change), when the idea apparently struck him:
“You people have a right to know how a candidate for president stands on issues, and so far President Coolidge has not told you where he stands on anything … so I am going to call him before you tonight and ask him to take this chair and tell me where he stands.” People in the auditorium began to crane their necks to see if Coolidge really was somewhere on the premises. I pulled a vacant chair and addressed it as though it had an occupant. “President Coolidge,” I began, “tell us where you stand on Prohibition.” I went on with rhetorical questions in this vein, pausing after each for a short period. Then I wound up: “There, my friends, is the usual silence that emanates from the White House.” The crowd roared in appreciation.
Schultz also reported that, in 1949, New York Senate candidate John Foster Dulles actually made an empty chair part of his stump speech. He traveled with it, pretending to debate his opponent, the former governor of New York.
Chairs have popped up, with mixed results, throughout American politics since then. Most of the time it's on the campaign trail.
But empty seats are arguably most effective on television. It should be no surprise, then, that they have a history there, too. Poynter's Andrew Beaujon reported on it in 2012 (there was a lot of reporting on empty chairs that year thanks to Eastwood):
Piers Morgan had one on his CNN show this month after U.S. Rep. Todd Akin canceled an appearance. Lawrence O'Donnell interviewed a chair in March, after a lawyer for George Zimmerman left the studio unexpectedly. Also on MSNBC that month, Thomas Roberts interviewed an empty chair after a guest didn't show -- and had to apologize after the network admitted it had brought her to the wrong studio.
Beaujon pointed out Obama has used his presence in a chair to make a political statement, too -- after Eastwood's stunt.
And if chairs are used to symbolize absence in politics, riderless horses have been used to symbolize the most permanent of absences. Both Abraham Lincoln's and John F. Kennedy's funeral processions had horses sans a rider, with their masters' boots pointed backward in their stirrups. It's a warrior tradition that dates back to the days of Ghengis Khan.
Obama's empty chair at Tuesday's State of the Union will also be used to symbolize death. And like many a politician before him, he is hoping an empty seat sends a message that an occupied one never would.