Photo licensed under Creative Commons, courtesy Flickr user Mark Sardella.

Scott Brown, the Republican who upset Democrat Martha Coakley in Massachusetts’ recent special Senatorial election, is now a United States Senator.

Brown’s swearing-in this afternoon caps off weeks of anxiety and finger-pointing for Democrats who had previously held a supermajority in the Senate. This fillibuster-proof majority was thought to be critical for the passage of divisive and persistently troubled health care reform legislation.

Sen. Brown told reporters today, “I can’t promise I will be right in every vote I make…I will do the very best job I can.”

He now assumes the Massachusetts seat held for 46 years by the late Ted Kennedy. Gov. Patrick appointed Kennedy’s now-defunct interim replacement, Paul Kirk, last fall.