A new poll shows Wisconsin Gov. Scott Walker (R) tied with his Democratic opponent Mary Burke two weeks after the same poll gave Walker a five-percentage-point lead. 

The Marquette University Law School poll finds that the two are tied at 47 percent among likely voters, with 4 percent undecided. In the poll two weeks ago, Walker led 50 percent to 45 percent. 

Walker gained national prominence with his fight against public sector unions in 2011, and he is a possible 2016 presidential candidate. Losing his reelection bid, however, could derail any hopes he has for higher office.

The poll shows a large shift in independents. Two weeks ago, Walker led among them 53 percent to 40 percent. Now, Burke leads 45 percent to 44 percent. 

The two candidates met for their first debate on Friday, which fell on the second of four days of this poll's surveying. The candidates clashed over a bill Walker signed last year requiring women to have ultrasounds before an abortion. Burke also criticized Walker on his jobs record and for opposing an increase in the minimum wage. 

Walker told the Milwaukee Journal Sentinel on Tuesday that he does not think the minimum wage "serves a purpose," though he said he did not want to repeal it. Burke supports raising it to $10.10 per hour, as does President Obama.

The poll also shows a striking shrinkage in the gender gap. Men favor Walker by only 2 percentage points, and women favor Burke by 1 percentage point. In previous polls since July, Walker's lead among men had been between 11 and 28 points, and Burke's among women between 6 and 18 points. 

In a move that could help Burke, the U.S. Supreme Court put a hold on Wisconsin's voter ID law on Thursday, meaning it will not be in effect for the election.