Hari Sreenivasan:

As millions of Americans in the United States and around the world celebrate today as the birth of Jesus, President Trump is taking credit for the return of the phrase "Merry Christmas."

He tweeted, "People are proud to be saying merry Christmas again. I am proud to have led the charge against the assault of our cherished and beautiful phrase. Merry Christmas."

William Brangham takes a closer look at what's behind the so-called war on Christmas.

(CHEERING AND APPLAUSE)