A pair of new polls show Republican Sen. Norm Coleman with a small lead among likely voters over Democrat Al Franken in Minnesota's U.S. Senate race.

An NBC News/Mason Dixon poll, conducted Monday and Tuesday, found that 42 percent of respondents supported Coleman, while 36 percent backed Franken. The results were within the margin of error of plus or minus 4 percentage points. The poll also found that 12 percent of respondents favored the Independence Party's Dean Barkley and that one in 10 Minnesotans were undecided.

In the other poll, by Rasmussen Reports, Coleman led Franken 43 percent to 39 percent. In that poll, which was conducted Tuesday and involved 500 likely voters, Barkley was favored by 14 percent, and 4 percent said they were undecided. The margin of error was plus or minus 4.5 percentage points.

Obama leads

In the presidential race, the Rasmussen poll and another one by Minnesota Public Radio and the Humphrey Institute showed Democrat Barack Obama with a strong lead over Republican John McCain in Minnesota.

The MPR-Humphrey Institute poll found that 56 percent of likely voters supported Obama, while 37 percent said they were for McCain and 6 percent were undecided. The survey of 451 likely voters was conducted between Friday and Tuesday and had a margin of error of plus or minus 4.6 percentage points.

In the Rasmussen poll, Obama led McCain 55 percent to 43 percent. Obama's margin has shrunk slightly, from 15 points last week. The Rasmussen poll has had Obama ahead in Minnesota for the entire campaign, although McCain closed to within four points in August.