A new poll from Marquette University Law School revealed that Wisconsin Marine veteran Kevin Nicholson (pictured) and businessman and State Sen. Leah Vukmir remain in a dead heat in the state’s Senate Republican primary.

The Marquette poll suggested that Vukmir leads with 34 percent support and Nicholson has 32 percent, with a seven percent margin of error.

“I think it would certainly be fair to call it a toss-up race at this point,” Marquette poll director Charles Franklin said.

Franklin added that “30 percent of Republican primary voters said they haven’t made up their mind,” making this race still largely undecided.

Both campaigns will likely ramp up their campaign ahead of the August 14 Wisconsin GOP primary.

The June Marquette poll shows that Nicholson has a higher favorability rating compared to Vukmir. The same poll found that Nicholson led by five points against Vukmir. Another survey conducted by Restoration PAC found that Nicholson led by 14 points over Vukmir.

The Wisconsin Senate Republican primary has quickly become a race between the establishment-backed Vukmir and the anti-establishment populist Nicholson.

House Speaker Paul Ryan, as well as Reps. Jim Sensenbrenner (R-WI), Sean Duffy (R-WI), and Glenn Grothman (R-WI) endorsed Vukmir for the Senate primary. The National Rifle Association (NRA) also backed Vukmir for the U.S. Senate.

In May, the Associated Press (AP) noted that Vukmir was “at one time in her career a grassroots conservative who ended up aligning with the establishment over the past several years.”

In contrast, Great America PAC, a pro-Trump super PAC, endorsed Nicholson in October. Conservative activist groups such as FreedomWorks and the Club for Growth both backed Nicholson.

Nicholson campaign spokeswoman Ronica Cleary signaled confidence even as they vie against the establishment Republican candidate.

“We’ve known for months that this race would be tight,” said Nicholson spokesperson Ronica Cleary. “Establishment and Washington Insiders are circling the wagons for Leah Vukmir, and it’s not surprising that the ballot is close.”

Nicholson also established himself as the pro-Donald Trump candidate by capitalizing on President Trump’s signature issue, immigration, and advocated for building a wall on America’s southern border as well as reforming immigration that will raise American wages.

In an interview with Breitbart News Sunday, Nicholson said, “We need an economically sustainable sensible plan that shuts down illegal immigration and has a merit-based sensible immigration policy… and that’s what we should be pushing for.”

“[On] the construction of a physical barrier, I’m a former combat engineer in the Marine Corps, and barriers work. They do stop people from crossing them, and that is the entire idea behind them,” Nicholson added.

In Nicholson’s first campaign ad, he chastised career politicians obstructing Trump’s ability to build a wall.

“The fact that Congress won’t build President Trump’s wall, won’t repeal Obamacare, and refuses to end illegal immigration, it’s a disgrace to everything we ever fought for,” Nicholson charged.