Former U.S. Sen. Rick Santorum is mulling a presidential run against Barack Obama in 2012, saying Mr. Obama's policies are "injurious to America" and driving Republicans to consider challenging him.

"I think not just me but a lot of people are going to take a look and see what they can do to try and confront this presidency, which many of us -- and you're seeing it from the tea parties and the like -- believe is injurious to America," the Pittsburgh native said in a conference call arranged by the Republican National Committee.

"I went from not considering [a presidential run] at all to saying I'll at least consider it. I think that's as far as I'll go three and a half years out," he said.

Since losing his 2006 Senate reelection to Democrat Bob Casey, Mr. Santorum, 51, has been a contributor to Fox News and an op-ed columnist for the Philadelphia Inquirer. He has positioned himself for a possible run by fundraising for the RNC and setting a meeting next month with conservative activists in Iowa, a key presidential state where his hard-right message could resonate with caucus voters.

Yesterday's talk with reporters was mostly in rebuttal to the Pittsburgh speeches by Mr. Obama and U.S. Sen. Arlen Specter. But in addressing recent criticisms of him by former John McCain aide Mark McKinnon -- who said a Santorum presidency would be "dangerous for America" but later apologized, Mr. Santorum said -- he again brought up a possible bid.

"I'm sure that Mark would still tell you he still has some concerns about my candidacy and that's well and good. I'm sure there will be many who do. That's part of the political process," he said.