(CNN) - With five days until Michigan's GOP presidential primary, a new poll indicates Mitt Romney and Rick Santorum are still tied for the top spot, but it appears the order has changed.
According to an American Research Group survey released Thursday, 38% of people likely to vote in Michigan's February 28 Republican primary say they are backing Santorum, the former senator from Pennsylvania, with 34% supporting Romney, the former Massachusetts governor. Santorum's four point advantage is within the survey's sampling error.
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Rep. Ron Paul of Texas is at 12%, with former House Speaker Newt Gingrich at 7%, and 8% undecided.
According to an NBC News-Marist survey released Wednesday morning, 37% of people likely to vote in Michigan's Republican presidential primary said they're backing Romney, with 35% supporting Santorum. Romney's two-point advantage was well within the poll's sampling error. The survey indicated that 13% are backing Paul of Texas, with 8% supporting former Gingrich.
Both polls were conducted before Wednesday night's presidential debate in Mesa, Arizona that was hosted by CNN and the Republican Party of Arizona.
Santorum surged in state and national polling after sweeping the February 7th contests in Colorado, Minnesota and Missouri. Michigan, where Romney was born and his father served as governor of the state in the 1960s, is turning into a make-or-break state for him. The 30 delegates up for grabs will be divided proportionally.
In Arizona, which holds its primary on the same day as Michigan, Romney appears to have a larger lead, according to the latest surveys.
In ARG's Michigan poll, Santorum leads Romney 49%-31% among likely Republican primary voters who describe themselves as supporters of the tea party movement, with Romney edging out Santorum 36%-30% among those who say they are not tea party supporters.
Santorum leads among men 39%-30% over Romney, with Romney edging out Santorum 39%-36% among women.
The American Research Group poll was conducted Feb. 21-22, with 600 likely GOP primary voters in Michigan questioned by telephone. The survey's sampling error is plus or minus four percentage points.
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