Specter Braces for Dem. Primary Challenge

It appears that Republican-turned-Democrat Sen. Arlen Specter is formally getting challenged in Pennsylvania's Democratic primary.

Rep. Joe Sestak, a former Navy vice admiral, has scheduled five campaign stops throughout the state on Tuesday. At the first, at a VFW hall in his suburban Philadelphia district, he's expected to announce his candidacy.

The announcement would not be a surprise. Sestak has already heavily campaigned in the state.

The five-term senator in April severed his decades-long ties with the Republican Party. He said, in part, it was to avoid a primary challenge with former Rep. Pat Toomey, who nearly beat him in the 2004 primary.