It’s difficult to imagine now that Michelle Obama was once hesitant to uproot her family to Washington, reportedly disdainful of living out her life in a political fishbowl teeming with piranhas. That tentativeness is long gone as she jets from city to city drumming up support and money for her husband’s re-election campaign. The First Lady touches down in Boston this afternoon for a reception and $5,000- to $25,000-a-head dinner at the Institute of Contemporary Art to benefit the Obama Victory Fund. At once glamorous yet able to easily connect with everyday people, Obama serves as star surrogate for boosting the Democratic base. She has been the ideological muscle behind the President, pushing him to champion what may be politically unpopular, but in her view just, causes like universal health care reform.