Ari Shapiro on Romney vs. Obama: Day 1

Mitt Romney and his wife Ann wave to supporters at a primary night gathering.

With wins in Wisconsin, DC, and Maryland, Mitt Romney now has half the delegates needed to win the nomination. And for the first time yesterday, President Obama attacked Romney by name. NPR White House Correspondent, Ari Shapiro, joins from Wisconsin to discuss the 2012 race and other political news.