Former consumer-protection head Elizabeth Warren inched closer to a U.S. Senate run from Massachusetts Thursday when she filed to launch an exploratory committee. A Warren adviser said her final decision will come sometime around Labor Day. Warren had become somewhat of a liberal superstar in her time as the chairwoman of the Congressional Oversight Panel, created in response to the 2008 financial collapse. But she could face as many as six others in a primary for the Senate seat, currently occupied by popular GOP incumbent Scott Brown. Republicans dismissed Warren’s possible candidacy, pointing out that she is originally from Oklahoma and has spent the last few years in Washington and as a Harvard professor.