Beltway sources tell Big Head DC that former Bush administration Press Secretary Tony Snow will make his debut on CNN tomorrow night during coverage of the Pennsylvania primary.

There’s some inside media speculation that this move may be CNN’s response to try to blunt praise Karl Rove has received as a pundit this primary season on FOX News.

But the bigger question is whether a short term former Bushie like Snow will even make an impact…look no further than former Bush communications director Nicolle Wallace on CBS — has anyone heard a thing about her?

For those of you who remember Snow before his White House days, he was a host of FOX News Sunday until 2003 at which point the network relegated him to radio to make room for Chris Wallace.

UPDATE: CNN confirms the move in a press release issued after Big Head DC broke the news:

Former White House press secretary Tony Snow will join CNN as a conservative commentator beginning today, it was announced by Jon Klein, president of CNN/U.S. A well-known and respected observer of politics with a longstanding news background, Snow will contribute to CNN as the network continues to broadcast winning political coverage.

Snow most recently served as press secretary to President George W. Bush from April 2006 to September 2007. For 10 years beginning in 1996, he appeared on Fox News Channel, hosting Fox News Sunday, Weekend Live with Tony Snow and other programs. From 2003 to 2006, The Tony Snow Show aired on Fox News Radio.

Before joining Fox, Snow served as a substitute “From the Right” co-host for CNN’s Crossfire.