(CNN) - A new poll indicates Rick Santorum is holding onto the top spot in Michigan, the native state of his chief rival Mitt Romney.
Thirty-seven percent of likely Republican primary voters said they would back Santorum, while 32% preferred Romney, according to a new American Research Group survey.Follow the Ticker on Twitter: @PoliticalTicker
While the five-point margin falls within the sampling error, it represents the same margin between the two candidates as a similar poll taken earlier than week. On Monday, Santorum held a 33% to 27% advantage over Romney.
Michigan, which holds its primary on February 28, has long been considered home turf for Romney, whose father once governed the Wolverine State. The candidate also carried the state in a much-needed victory in the 2008 Republican primary.
In the last few days, Michigan airwaves have been prime battleground for the campaigns and super PACs, with a major cash flow pouring into ad buys.
Texas Rep. Ron Paul came in third place with 15% support, according to the new survey. Meanwhile, former House Speaker Newt Gingrich came in fourth with 10%, down 11 percentage points since Monday's results. Five percent were undecided.
Also notable, among likely Republican primary voters who will definitely vote in the primary, Santorum held an even wider advantage over Romney, 38% to 30%. And among self-identified independents and Democrats, Santorum led with 40% to Romney's 27%.
Michigan has an open primary in which any registered voter can participate.
The American Research Group conducted the survey between February 15 and February 16, interviewing 600 likely Republican primary voters by phone, with a sampling error of plus or minus four percentage points.
