Former Pennsylvania Gov. Tom Ridge is considering running for the Republican Senate nomination in his home state, according to a senior Republican aide with knowledge of the situation. National and Keystone State Republicans have been publicly and privately urging Ridge to consider a Senate bid since Sen. Arlen Specter (Pa.) announced earlier this week that he was switching parties and would run for re-election as a Democrat in 2010. Specter said he switched parties because he could not win a primary against conservative former Rep. Pat Toomey (R-Pa.), who is popular with the party’s base but whom many national Republicans believe cannot win the general election — especially against a 29-year incumbent who is viewed favorably and gets high marks from Democrats. Ridge’s moderate politics and national profile would make him a more viable candidate in the general election. A former six-term House Member, Ridge is still popular in Pennsylvania, where he served as governor from 1995 to 2001. He left office to be President George W. Bush’s first secretary of Homeland Security but retired from the Cabinet in 2005 and joined the private sector. Ridge, however, has remained in the public spotlight. He campaigned vigorously alongside Sen. John McCain (R-Ariz.) during his bid for the presidency last year. The former governor was also often mentioned as a contender to be McCain’s pick for vice president, even though Ridge supported abortion rights.Rep. Jim Gerlach (R-Pa.) also said he will consider running for Senate in 2010, although he has already formed an exploratory committee to run for governor next year. Party leaders have also mentioned another moderate Republican running for governor, former U.S. Attorney Patrick Meehan, as a potential candidate to face off with Toomey in the primary. The Democratic Senatorial Campaign Committee is supporting Specter to be the party’s nominee, but the field so far has not been cleared for the former Republican. Former National Constitution Center President Joe Torsella (D) is still in the race, plus Rep. Joe Sestak (D-Pa.) indicated Friday on a cable television news show that he is still very seriously thinking about running against Specter in the primary.