BLITZER'S BLOG: When will President Obama start naming names?

(CNN) – Vice President Joe Biden is now willing to name names in going after Mitt Romney, Rick Santorum and Newt Gingrich. President Obama is now increasingly willing to go after them but he’s still avoiding naming names.

Here’s how he criticized Romney on health care mandates this week in an interview with Public Radio International.

Watch The Situation Room with Wolf Blitzer weekdays at 4pm to 6pm ET and Saturdays at 6pm ET. For the latest from The Situation Room click here.