Sen. Lindsey Graham: Santorum evokes Reagan on foreign-policy stance

"Ronald Reagan confronted the challenges of his time," added Graham, who serves on the Senate Armed Services Committee. "He did not isolate America."

The warm comments from the junior senator from South Carolina, however, did not constitute an endorsement. Graham instead spoke a kind word about each of the front-runners for the GOP nomination for the presidency. 

"Gov. Romney looks like the president; he has a very good business record," Graham said. "Perry has been a good governor. Herman Cain is resonating with people."