Mitt Romney now trains fire on Rick Santorum in addition to Newt Gingrich

By Shira Schoenberg, Globe Correspondent

Republican presidential candidate Mitt Romney is going after a new foe: former Pennsylvania Senator Rick Santorum.

Until now, the former Massachusetts governor has focused most of his attention on former House Speaker Newt Gingrich, who beat Romney in the South Carolina primary and has been his most formidable opponent so far, despite Santorum’s narrow victory over Romney in the Jan. 3 Iowa caucuses. Today, however, Romney’s campaign appeared to pivot, trading barbs with Santorum over health care and earmarks.

“Rick Santorum is a nice guy, but he is simply not ready to be president,” former Minnesota Governor Tim Pawlenty, a Romney surrogate, said in a statement sent out by the Romney campaign. “Plus, he wants Minnesota conservatives to believe he’s as conservative as they are, but he’s not.”

The attacks come a day before Republican caucuses in Minnesota and Colorado and a non-binding primary in Missouri. While Romney is widely expected to win Colorado, the Minnesota race could be tight. Romney won Minnesota’s caucuses in 2008. But he is not campaigning in Minnesota this week, while all his opponents are. Missouri could also be a close race between Romney, Gingrich, and Santorum.

On NBC’s Meet the Press Sunday, Santorum said Romney “sided with big government” on issues including health care and cap and trade as a response to global warming. Romney’s Massachusetts health care overhaul included an individual mandate, similar to President Obama’s national reform. Romney has defended his Massachusetts plan, but opposed Obama’s. Romney joined a regional cap and trade energy pact as Massachusetts governor, then pulled out.

This morning, Romney responded with a press release chronicling Santorum’s “false attacks on Massachusetts health care,” citing several stories on the independent fact-checking websites FactCheck.org and PolitiFact.com.

The Romney campaign scheduled a conference call with Pawlenty to talk about Santorum’s “long history of pork-barrel spending,” in which Pawlenty mentioned earmarks Santorum voted for including the so-called “Bridge to Nowhere” in Alaska. In an e-mailed statement, Pawlenty described Santorum as a “leading earmarker and pork-barrel spender.”

Santorum responded with a release tagging Romney as a moderate who is out of touch with Republican politics. “Governor Romney does what he always does and directs his well-funded attack machine to destroy the opponent,” said Santorum spokesman Hogan Gidley. “Mitt Romney’s act is tired, old and wearing thin with voters….In the Republican Party we have a name for someone who supports government health-care mandates, big bank bailouts, and radical cap and trade initiatives - we call them Democrats.”

The Santorum campaign pointed to Romney’s requests for federal money to fund the 2002 Olympics, which Romney managed, and the Big Dig construction project in Boston.

The Romney campaign then sent out Santorum’s 2008 endorsement of Romney, in which Santorum called him a conservative.

Then the Santorum campaign returned to health care– sending out a release arguing that Romney’s health care plan served as the framework for Obama’s health care overhaul, referencing a comment Pawlenty made during his presidential campaign last year. “As Governor Tim Pawlenty so aptly said, RomneyCare should be called ObamneyCare,” Gidley said.

The back-and-forth illustrates the growing negativity on all sides in the GOP primary, as Santorum, Gingrich, and Ron Paul fight to become the viable alternative to Romney, and to prevent Romney from racking up enough victories to be seen as the inevitable nominee. After tomorrow’s races, there will be three weeks before the next primaries. Particularly if Romney does not dominate, voters can expect the sniping to continue.