Former Sen. Russ Feingold (D-Wis.) has a slim 5-point edge over incumbent Sen. Ron Johnson Ronald (Ron) Harold JohnsonGOP set to release controversial Biden report Democrats fear Russia interference could spoil bid to retake Senate The Hill's Morning Report - Sponsored by The Air Line Pilots Association - White House moves closer to Pelosi on virus relief bill MORE (R-Wis.), according to a new poll.

Feingold leads Johnson 49 percent to 44 percent in the Marquette University Law School survey released Wednesday.

ADVERTISEMENT

Pollsters also found Feingold’s advantage grows with the Badger State’s registered voters when the race becomes a three-way pick with the libertarian candidate; Feingold grabs 45 percent to Johnson’s 38 percent in that scenario, while libertarian Phil Anderson takes 8 percent.

Johnson is widely considered one of the most vulnerable GOP senators in the Democrats' push to take control of the Senate. Democrats need a net gain of four seats if they win the White House, or five seats if they lose the presidency.

Despite defeating Feingold in 2010 following a national backlash against ObamaCare, Johnson faces an uphill battle in Wisconsin, which went blue for President Obama during both the 2008 and 2012 election cycles.

Wednesday’s results found registered voters view Feingold slightly more positively than Johnson despite the latter’s status as their sitting senator.

Forty percent see Feingold favorably, while 32 percent view the former three-term senator unfavorably and 24 percent had not heard enough for an opinion.

Thirty-four percent view Johnson favorably, meanwhile, versus 35 percent who consider him unfavorably and 30 percent who had not heard enough for an opinion.

The Marquette University Law School conducted its latest sampling of 801 registered voters in Wisconsin via interviews from July 7-10. It has a 4.1 percent margin of error.

Feingold’s lead over Johnson grew slightly since last month, when he nabbed a 4-point advantage in their competitive rematch over Wisconsin’s Senate seat.

Feingold took 45 percent to Johnson’s 41 percent among Wisconsin’s registered voters in June’s edition of the Marquette University Law School survey.

June’s version of the poll sampled 800 registered voters via phone interviews conducted from June 9-12. It had a 4.4 percent margin of error.