Republican presidential candidate Rick Santorum is defending his use of spending earmarks in Congress, saying some were necessary for defense or health programs.
The former Pennsylvania senator says there are good and bad earmarks, and that he fought to end the practice of targeted spending amid concerns that lawmakers were abusing it.
GOP front-runner Mitt Romney has been pounding Santorum on the issue. Santorum upset Romney this week by winning nominating contests in three states. Romney is hoping the relentless criticism will cut into the base of tea party support that helped lift Santorum to victory.
Campaigning in Oklahoma City, Santorum specifically defended targeted spending for the V-22 Osprey helicopter and a human tissue medical program in Pittsburgh.
He declined to identify any earmarks he regretted.