HARRISBURG — Former Sen. Rick Santorum of Pennsylvania, a potential Republican presidential candidate, warned Monday that conservatives should be wary of the libertarian strain of thought in the "tea party" movement.

Santorum was responding to a question about Kentucky Republican Senate nominee Rand Paul, who last week said he disagreed with the idea that the federal government should have a right to bar private businesses, such as restaurants, from discriminating on the basis of race, as it did in the 1964 Civil Rights Act.

"I don't think the libertarians have it right when it comes to what the Constitution is all about ... or when it comes to our history," Santorum said at the Pennsylvania Press Club. "When there are clear wrongs in society, injustice in society — sure, you handle it at the local level if you can — but when the local and state governments are in cahoots with the injustice, then the federal government has to step in and do something."

Santorum also dismissed Pennsylvania Democratic Senate candidate Joe Sestak as "a loose cannon" and predicted a November victory for Republican Pat Toomey.

Santorum said he noticed a "sense of anxiety" among Americans as he stumps for conservative causes. Repeat trips to Iowa, South Carolina and New Hampshire — all important early states in the GOP presidential nominating process — in the last several months have put him on the list of possible candidates for 2012.

Joking that he was amazed at how a little presidential buzz had drawn people to hear his ideas, Santorum said he would not make a decision about whether to run until several months after the midterm elections in November.

Santorum, 52, served two Senate terms before losing a race for re-election in 2006. He is a fellow at a conservative think tank, a commentator on Fox News and talk radio, and writes a biweekly column for The Philadelphia Inquirer.

After his speech, Santorum predicted that Toomey would defeat Sestak in the fall.