Barack Obama has begun stumping for Vice President Kamala Harris. Bill Clinton is holding a series of campaign events for her in battleground states. 

Yet the Democratic superstar many members of the party would like to see helping Harris has been absent from the campaign trail so far.

With just 20 days until the election, Michelle Obama has worked behind the scenes to boost turnout in key swing states, but she has yet to schedule an official appearance for Harris since the Democratic National Convention. Two people familiar with the matter said she has expressed fresh concerns about security following two assassination attempts against former President Donald Trump.