By Brendan O'Brien
MILWAUKEE (Reuters) - Wisconsin Democratic Congresswoman Tammy Baldwin could make history next week as the first openly gay member of the U.S. Senate, according to the final poll before the November 6 election released on Wednesday by the Marquette University Law school.
The poll showed Baldwin had a 47 to 43 percent lead among likely voters over Republican former governor Tommy Thompson, with 10 percent undecided or offering no preference. Two weeks ago, Thompson lead Baldwin 46 to 45 percent.
Poll Director Charles Franklin accurately predicted the outcome of the state's hotly contested vote on the recall of Governor Scott Walker last summer. Two weeks before the June 5 election, he predicted a 52 to 45 percent win for Republican Walker, who subsequently won 53 to 46 percent.
The poll in the Senate race surveyed 1,243 likely voters from October 25 to 28 and had a 2.8 percent margin of error.
The winner will fill the seat being vacated by retiring Democrat Herb Kohl, who is finishing his fourth term in the Senate.
Republicans need a net gain of four seats to have an outright majority in the Senate, and would have effective control if they gain three seats and presidential candidate Mitt Romney is elected. The vice president casts the tie-breaking vote when the 100-member Senate is evenly divided.
The Marquette Law School poll also showed a President Barack Obama with a comfortable 51 to 43 percent lead over Romney, with five percent undecided and one percent voting for a third party candidate.
Other polls of Wisconsin show the presidential race closer.
(Editing by Greg McCune and Jackie Frank)