Connecticut: Rep. Chris Murphy (D)
The third-term congressman announced on January 20 that he was running for the seat of retiring Sen. Joe Lieberman (ID).
"I only take this step because I believe I can be an even stronger voice for change in the United States Senate," Murphy said in a statement. Murphy also made a video announcement on his website and hosted an event the evening of his announcement in Cheshire, Conn.
Murphy reported raising $1.1 million in the first quarter of 2011, more than double that of his Democratic primary opponent, former Connecticut Secretary of State Susan Bysiewicz.