She's starting out Monday in Stamford, Conn., headlining a fundraiser and rally for Senate candidate Richard Blumenthal. He's the state attorney general and is in a tight race with Republican Linda McMahon to replace retiring Democratic Sen. Chris Dodd.
The first lady later will join Vice President Joe Biden's wife, Jill, at fundraisers in Manhattan that are expected to pull in $1 million for the Democratic National Committee. One event is a concert hosted by actress Sarah Jessica Parker with entertainment by singer Patti LaBelle.
Obama has made several campaign appearances in recent days as Democrats brace for expected deep losses in next month's midterm elections.