For the past decade, Pat Toomey has been known as a right-wing agitator — a three-term congressman who famously challenged moderate Republican Arlen Specter in a 2004 Senate primary. The 51-year-old Harvard graduate is also a former president of the Club for Growth, a group that often fights the Republican establishment. But his recent bipartisan work on gun control, among other issues, has turned the freshman senator into an unexpected pragmatist.