President Barack Obama sought to rally Massachusetts Democrats Sunday, telling a large crowd at Northeastern University in Boston that they have a “unique and special responsibility” to fill the late Sen. Edward Kennedy’s seat in Tuesday’s special election.

And the best person to fill that seat, he said, is Massachusetts Attorney General Martha Coakley (D).

“Martha knows the struggles Mass working families face,” said Obama, pointing to her humble roots in North Adams, Mass and saying she “has a track record” of putting people first.