Mitt Romney sweeps five primaries and all but locks up the GOP nomination. Even Newt Gingrich agrees Romney is the presumptive nominee. More veepstakes speculation on Sen. Marco Rubio of Florida and Sen. Rob Portman of Ohio. Two centrist House Democrats bite the dust in Pennsylvnaia, while Utah GOP Sen. Orrin Hatch lives to fight another day.
NPR's Ken Rudin and guest host Mara Liasson have the latest political news in this week's roundup.