A new poll of Minnesota Republicans shows a volatile electorate in advance of Tuesday's presidential contest.

The poll, from Public Policy Polling, found Rick Santorum with 29 percent of the vote, Mitt Romney close behind with 27, followed closely by Newt Gingrich with 22 percent and Ron Paul with 19.

With a margin of error of 4.8 percent and 37 percent saying they could change their minds, the numbers show any of the four candidates could pull out a Tuesday straw poll win.

The candidates are all flocking to Minnesota to sway those mind changers. Santorum is in Minnesota today, Paul was in the state Saturday and will return Monday, Romney will return on Monday afternoon and Gingrich will make his visit to Minnesota on Monday evening.

Late last month, the polling firm showed Gingrich with a large but clearly tenuous lead in Minnesota. Back then, 59 percent of Minnesota Republicans said they had a favorable opinion of Gingrich and 25 percent said they viewed him unfavorably. In the more recent poll, which came after Romney hammered Gingrich for weeks, the former U.S. House Speaker's favorables slipped to 49 percent and his unfavorable rating grew to 41 percent.

A win in Minnesota will add to Romney's air of victory, after first place finishes in Nevada, New Hampshire and Florida, but could give the other three candidates a sign that continuing on is worthwhile.

Here are the full polling results:

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