Unwaveringly popular and seen as "cool," Barack and Michelle Obama are throwing not just their political weight but also their star power behind Kamala Harris in the final stretch of the U.S. election.

With just 10 days to go before the Nov. 5 vote, Michelle Obama appeared before a rapturous Harris rally Saturday in Kalamazoo, Michigan, walking on stage to a deafening standing ovation.

Energizing the crowd, she had the audience chanting "Do something!" a refrain from her speech at the Democratic National Convention in August, when she urged Harris's voters to take action.