Demi Lovato Tackles Mariah Carey's "All I Want for Christmas is You" at "Christmas in Washington"

Taking on the newest true holiday classic, Demi Lovato performed Mariah Carey's "All I Want for Christmas is You" at the 2012 "Christmas in Washington" special on Friday (December 21).
The "X Factor" judge was backed by a choir as she belted out the hit song in a black leather jacket with gold trim.

Though her future as a judge on the competition show is uncertain after this week's finale, it's clear that the 20-year-old singer is sad to see the season end.
On Friday she tweeted, "I think the Mayans knew that The X Factor USA was gonna end last night. I feel them though.. feels like the end of the world to me too.."
Check out Demi's performance below.