President Obama Tweets Tribute to David Letterman

Obama appeared on Letterman seven times.

Obama, who has appeared on Letterman seven times, shared a salute to the "Late Show" legend shortly after he announced his retirement.

As news of David Letterman's impending retirement from Late Show reverberated through the media and entertainment world late on Thursday, a friend in a very high place tweeted his own salute. 

"There are more than 10 reasons #DavidLetterman will be missed," President Barack Obama wrote from his official Twitter account. 

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Obama sat down with Letterman on the Late Show seven times, twice while president.

When Obama appeared on the show in 2008, it was the first time -- from throughout Letterman's tenure from 1993 through 2008 -- that a sitting president was featured as a guest on the show. The visit generated some controversy in conservative circles over the propriety of a presidential appearance on such a program, but it ultimately blew over, while also giving Letterman a then-record ratings night.