Tom Ridge spent much of 2009 publicly mulling a bid for Senate in Pennsylvania, but he opted not to run and on Thursday endorsed Republican Pat Toomey’s bid.
"As a member of Congress Pat consistently fought for taxpayers, and in today’s economic climate, that trait is more important than ever," the former governor said in a statement.
Toomey said he was "honored" to have the backing of Ridge, who also served as Homeland Security secretary.
The endorsement comes as a new report shows Toomey is one of the top recipients of campaign contributions from Wall Street and financial interests.
The industry's contributions, which favored Democrats in recent election cycles, are now helping Republicans vie for control of the Senate.
Between February and June, financial, insurance and real estate interests contributed heavily to five Senate Republican candidates, including Toomey, who received $728,000, according to data compiled by the Center for Responsive Politics.