Gov. Tim Pawlenty's popularity among his constituents keeps bobbing around.

A new SurveyUSA poll conducted last month found that 51 percent of Minnesotans said they approve of the job Pawlenty's doing.

That's up from February, when 48 percent of the state's residents give him a thumbs-up on his performance; it's down from January, when his approval rating stood at 54 percent.

In the new poll, conducted March 20-22, 46 percent of the state's residents said they didn't approve of the job Pawlenty is doing.

Pawlenty has been hovering near what political analysts consider a danger zone, when a politician enjoys the support of fewer than half of poll respondents.

Since 2003, when Pawlenty took office, he has routinely had an approval rating comfortably above 50 percent, as measured by the Star Tribune's Minnesota Poll. The sole exception occurred late that year, when it briefly dipped to 49 percent, in the wake of a bruising legislative session.

Pawlenty has not said whether he'll seek a third term in 2010.

The poll, conducted for four Minnesota television stations, has a margin of sampling error of 4.1 percentage points. Six hundred Minnesotans were interviewed.