(TheHill)…Rick Santorum has overtaken Mitt Romney in the race for the GOP primary vote in Michigan, a state long considered a lock for Romney that has become a make-or-break test for his campaign.  New polls from Republican-leaning American Research Group and the Democratic-leaning Public Policy Polling both give Santorum the lead in Michigan, where Romney grew up and his father was a popular governor. 

The PPP poll released Monday found Santorum at 39 percent, ahead of Romney with 24 percent, Ron Paul with 12 percent and Newt Gingrich at 11 percent. Similarly, the American Research Group poll found Santorum with 33 percent, followed by Romney at 27 percent, Gingrich at 21 percent, and Paul at 12 percent.  After a trio of wins last week in Colorado, Minnesota and Missouri last week, Santorum has taken the fight for the GOP nomination to Michigan, where he plans to “talk about jobs and opportunities for everybody in America to rise.”

A victory for Santorum in that state would be devastating for Romney and cast doubt on his status as the inevitable GOP nominee. Romney won the state in 2008, beating Arizona Sen. John McCain by nine points, and it’s viewed as friendly territory for the former governor.  It’s not unusual for a candidate to receive a big boost in the polls after a round of wins. Newt Gingrich led in the polls in Florida shortly after he won South Carolina’s contest and Romney ended up winning that state.  But Santorum’s campaign has been on the upswing and his aides have claimed he raised $3 million in three days following his wins last week.