Chris Carney

As the fate of President Obama s signature piece of legislation, the Affordable Care Act, rests on a decision made by nine Supreme Court justices, the Up w/ Chris Hayes panelists - including former President Obama advisor Neera Tanden, the Washington Examiner's Tim Carney, Dr. Claudia Fegan, and Yale University law professor Akhil Amar - discuss the impact of a partisan court.

Insight on Mitt Romney and Rick Santorum's tax plans, with Chris Chocola, Club for Growth; Brad Thor, author & Santorum supporter; and David Carney, former White House political director under George H.W. Bush.

Best Buy is shaking things up today, acquiring its British partner's stake of their US mobile phone joint venture for $1.3 billion, with Chris Horvers, J.P. Morgan, and John Carney, CNBC.com.

Lars Bakken, Chris Carney and Derek Carroll give us a preview of what to expect during the Halo: Reach beta. Find out about the new matchmaking system, armor customization, controls, modes and more in this preview of Halo: Reach.