MADISON, Wis. (AP) -- Wisconsin's tightening race for the U.S. Senate may signal a shift to the left in a state that has been leaning to the right ever since Republicans scored significant gains following the 2010 election.
A new Marquette University Law School poll released Wednesday shows Democrat Tammy Baldwin with a narrow 4-point lead over Republican Tommy Thompson. The poll of 894 likely voters done Sept. 27 through Sunday has a margin of error of plus or minus 3.3 percentage points.
Baldwin's lead is down from 9 points two weeks ago.
Marquette pollster Charles Franklin says Baldwin's lead dropped due to a shift in support from independent voters.
The poll also shows President Barack Obama with an 11-point lead over Republican Mitt Romney.
Obama plans to campaign in Madison on Thursday.