You think the President is afraid to put a New Testament verse on his card because it's not PC. You wonder why he didn't. It's a silly thing to fret about.
This whole thread is silly. The President is a Christian who has spoken openly about his faith in Jesus Christ. No one questions that except a few picky, unaware, bullheaded, politically motivated people around here.
He and Laura sent a lovely Christian Christmas card, which people were thrilled to receive. He is the first President to put Scripture in a card, and you are griping because it's from the Old Testament. And in addition, I think you are imagining the absence of New Testament verses around here.
Why don't you find something important to worry about, thank the Lord that we have a GODLY CHRISTIAN President who honors the LORD with his life, and have a Merry Christmas, knowing that your President is glorying in the birth of the Messiah, Jesus Christ, just as you are.