We've all seen Barack Obama's smile. We've even heard him laugh as others poked fun at him, or as he poked fun at others.
But on Saturday, speaking to House Democrats on Capitol Hill in advance of the momentous health-care reform bill vote, his sense of humor was put to a higher purpose - and yet kept its genuine hilarity.
Speaking about his proposal, and about the debate that ensued, Obama called his supporters to his side and dismissed his detractors with a cleverly worded line.