Bob McDonnell clams up about VP possibility

This is based on just one interview, but there appears to be a shift in the way Virginia Gov. Bob McDonnell discusses whether Mitt Romney's presidential campaign is considering him as a possible vice presidential candidate.

He's no longer talking about it at all.

"I'm not discussing the vice presidential vetting process," McDonnell said Tuesday on WTOP radio's "Ask the Governor" program when questioned about whom Romney will choose. "You can address those questions to the Romney campaign."

In the past, McDonnell has denied that he had been in contact with Romney's vetting team.

The unwillingness to talk about the process could be a sign that McDonnell, who endorsed Romney during the Republican primaries and has campaigned for him, is now officially in the running for the No. 2 job. (Of course, it could also mean nothing at all.)