More on Michelle ObamaIn three short days, Michelle Obama has expanded on her role as mom-in-chief to take on new and somewhat unusual duties for a first lady - actively pitching her husband's economic stimulus package, now facing trouble in the Senate. As she makes a "get-to-know-you" tour of federal agencies, Obama is using her considerable platform to amplify the message coming out of the White House: pass the stimulus plan, and pass it now.