The presidential race in Minnesota appears to be tightening, according to a new poll.

The survey of 700 likely voters by the polling firm Rasmussen Reports shows that the race between Democrat Barack Obama and Republican John McCain is a statistical tossup.

Obama leads 46 percent to 42 percent, within the poll's margin of sampling error of 4.5 percentage points.

The poll, conducted Wednesday, shows that Obama's position has weakened in the past month; a Rasmussen poll conducted in July showed him with 49 percent and McCain with 37 percent.

Rasmussen also released a new poll on the U.S. Senate race in Minnesota, which shows a tossup between Republican Sen. Norm Coleman and Al Franken, his leading DFL challenger.

Each candidate is supported by 45 percent of likely voters, marking the fourth time a poll by the firm has shown the candidates within 3 percentage points of each other, leaving the race essentially tied.

Most other polls measuring the Senate race have shown Coleman with a comfortable lead over Franken.

The new presidential poll mirrors one conducted last month by Quinnipiac University, which found that Obama was leading McCain 46 to 44 percent among the state's likely voters, also a statistical tie.

The trend in recent polls has shown McCain gaining ground on Obama since spring, nourishing Republican hopes that they can flip Minnesota out of the Democratic column for the first time since 1972.

In light of the intense speculation swirling around Gov. Tim Pawlenty's vice-presidential prospects, the poll offers a mixed message.

Thirty-four percent of those polled say they are less likely to vote for McCain if Pawlenty is the vice presidential nominee, while 28 percent say it makes them more likely to vote for McCain. Thirty-five percent say it will have no effect on how they vote.

Bob von Sternberg • 612-673-7184