Rep. Ed Markey running for Senate in Massachusetts

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Massachusetts Democratic Congressman and Dean of the Massachusetts delegation, Ed Markey, became the first person to officially announce that he'll run for John Kerry's Senate seat. MSNBC's Lawrence O'Donnell predicts that Markey will win the special Election. MSNBC's Jonathan Capehart and Ari Melber weigh in on who they think will throw their names into the ring and which Democrat stands the best chance of defeating Scott Brown if he decides to run.