Mitt Romney continued on the path to securing the Republican presidential nomination last night, winning all 37 delegates in Maryland, all 16 delegates in the District of Columbia, and at least 30 delegates in Wisconsin.  In a speech after the results were tallied, Rick Santorum vowed to keep fighting. Wisconsin Public Radio's capitol reporter  Shawn Johnson and The Takeaway Washington correspondent Todd Zwillich join us to look at the big picture from last night's results as well as a look at President Obama's own campaigning.