Congressman Pat Toomey (R-Penn) is honoring his pledge to step down from the House after three terms and is preparing to formally announce Friday that he will challenge fellow Republican Senator Arlen Specter next year.

A number of the Members of the Republican House delegation have already said they are supporting Senator Specter's bid for a fifth term. Republican representatives Greenwood, English, Shuster and Platts are all publicly backing Specter for re-election. The White House has sent clear signals that they would support Specter in the primary.

The Republican Senatorial Campaign Committee (RSCC) has also indicated that they will stand strongly behind incumbent Specter. This differs from last year when the RSCC indicated that they would support incumbent then-Senator Bob Smith of New Hampshire in another Republican primary, but did little to help him.

Representative Toomey's chances in the primary don't appear to be strong. Specter already has 10 times as much cash on hand as Toomey.