(Charlie Neibergall, File/Associated Press)

Santorum opposes abortion rights and favors a constitutional ban on same-sex marriage. He takes a hawkish line on foreign policy, saying he would bomb Iran’s nuclear facilities unless they were opened for international arms inspectors.

“I’ve voted toughly over the years to cut spending and to rein in entitlements,” he said recently.

Not always. Santorum, who rose to the No. 3 GOP leadership post in the Senate, supported the sweeping No Child Left Behind education reform bill that conservatives complain gave too much control to the federal government. He has said he regrets his vote.

In 2003, Santorum was a leading advocate for extending Medicare prescription drug benefits to seniors, a measure that conservative critics branded as a massive entitlement expansion that would run up the federal budget deficit by hundreds of billions of dollars. He now says the vote was a mistake.

Santorum also voted for a massive highway bill in 2005 that was stuffed with earmarks, including the infamous “Bridge to Nowhere” in Alaska.

He fought food stamp cuts in 2005 and has pushed hard to get more federal money for Amtrak and the Low Income Home Energy Assistance Program, which provides fuel aid to the poor. Both are programs popular in Pennsylvania but considered by many conservatives to be examples of a bloated federal government.

Santorum worked to extend subsidies in 2005 for Pennsylvania’s dairy farms. The $1 billion, two-year national program paid dairy farmers when milk prices dropped.

In 2002, Santorum went to bat for retired steelworkers. He pushed a plan to use some revenues from a Bush administration proposal to drill for oil in the Arctic National Wildlife Refuge in Alaska to pay some health and pension costs of about 600,000 retirees from bankrupt steel companies, a key constituency in Pennsylvania.

Santorum has already come under fire from his GOP rivals for his heavy use of earmarks, which are a favorite target for tea party activists who see them as wasteful.