Standing before a soaking-wet Washington DC crowd, President Barack Obama danced with an elf and remembered Nelson Mandela as he lit the National Christmas Tree yesterday. 

ABC News is reporting that Obama took a normally-lighthearted event and took a minute to remember the recently-deceased former South African vice president. "This year, we give a special measure of gratitude for ... a man who championed that generosity of spirit. In his life, he blessed us with tremendous grace and unbelievable courage. And we are all privileged to live in a world touched by his goodness," said Obama of Mandela.

But the festivities weren't all somber -- Obama took time to dance with an elf and a dancer from Mariah Carey's dance troupe (well, he tried to, anyway) as the First Family -- First Lady Michelle, and First Daughters Malia and Sasha -- looked on joyfully. 

"For 91 years, the national Christmas tree has stood as a beacon of light and a promise during the holiday season. During times of peace and prosperity, challenge and change, Americans have gathered around our national tree to kick off the holiday season and give thanks for everything that makes this time of year so magical - spending time with friends and family, and spreading tidings of peace and goodwill here at home and around the world," he said. 

And, in typical Obama fashion, he made a self-deprecating joke at his own expense. "This show is always a great way to get in the holiday spirit. Every year, I rehearse my own little act, just in case. But it seems like, yet again, they couldn't find space to squeeze me into the program," he joked. "You are lucky I'm not singing."