On September 12, 2009 (his 50th birthday), Brown announced his run for the U.S. Senate seat that became vacant with the death of Ted Kennedy, saying the state "needs an independent thinker." "Washington Post" columnist Kathleen Parker said that Brown's political positions did not fall neatly into party lines, and called Brown "mainstream in a nation that defines itself as mostly conservative." Boris Shor, political scientist at the Harris School of Public Policy, described Brown as a liberal Republican by national standards, but well-suited for his Massachusetts constituency. Shor explained the support Brown was receiving from the conservative national Republican Party as due to their "decentralized decision" to support the candidate most likely to win.