Democratic presidential candidate Barack Obama has rebuilt his lead over Republican John McCain in Minnesota and now has a margin of 10 percentage points, according to a poll released Thursday.

But the poll, sponsored by Minnesota Public Radio and the University of Minnesota Humphrey Institute of Public Affairs, indicates the race is still fluid. It suggests McCain could close the gap and possibly win in Minnesota, if he picks Gov. Tim Pawlenty as his running mate.

Forty-eight percent of those answering the survey said they support Obama for president, compared with 38 percent for McCain. Three percent favored independent Ralph Nader and 1 percent supported Libertarian Bob Barr.

The telephone survey of 763 likely voters was conducted Aug. 7-17. The margin of sampling error is plus or minus 3.6 percentage points.

Despite the double-digit margin, the race in Minnesota remains fluid, said Larry Jacobs, director of the Humphrey Institute's Center for the Study of Politics and Governance. Jacobs said 10 percent of those polled were undecided, and supporters of each candidate said they might change their minds.

"So this race is very much up in the air and up for play," he said.

An independent poll of likely Minnesota voters released in July found that McCain had erased Obama's once-commanding lead in Minnesota. The poll conducted by Quinnipiac University had Obama up 46 to 44 percent, which was within the poll's margin of sampling error. The same pollsters in June put Obama 17 percentage points ahead of McCain.

ASSOCIATED PRESS