Montana rancher and state auditor Matt Rosendale told Breitbart News in an exclusive statement on Friday that Sen. Jon Tester (D-MT) “voted against building the wall” and actively opposed the Trump agenda.

Rosendale, who hopes to unseat Tester in the 2018 midterm elections, capitalized on President Donald Trump’s signature issues of immigration reform and building a wall on America’s southern border. The Montana state auditor has also chastised Tester for actively opposing building the proposed border wall as well as Trump’s legislative agenda.

Rosendale told Breitbart News, “Once again, Jon Tester’s actively opposing the Trump agenda and embracing Chuck Schumer and Nancy Pelosi’s radical pro-illegal immigration agenda. Tester voted against building the wall, he’s protecting sanctuary cities and backing legislation to codify catch and release into federal law. I’ll stand with President Trump and get tough on illegal immigration.”

Sen. Tester voted against funding Trump’s promised border wall in February. In October 2017, Sen. Tester suggested that Trump’s border wall would amount to a waste of taxpayers dollars.

Tester said that “We cannot waste taxpayer money with something that won’t be the most effective thing possible.”

“The president’s proposed border wall will cost taxpayers upwards of $1.6 billion, and the White House has no plan about how they’re going to spend that money,” Tester said last year. “We have a plan that will make our border even more secure and address other security gaps without wasting billions of taxpayer dollars.”

Marnee Banks, a spokesman for Tester, told Politico this week that “negotiations are ongoing” regarding including wall funding in the September spending bill.

Banks told Politico, “Jon wants to secure our border and is willing to make responsible investments in manpower, technology, fencing and, in places, a wall. However, he has concerns about the cost of the wall to American taxpayers.”

Several Senate Democrats face increasingly competitive re-election campaigns and as a result, moved to embrace the president’s immigration agenda.

On Wednesday, Sen. Joe Donnelly (D-IN) caved and suggested that he will support partially funding Trump’s border wall in a September spending bill.

Sen. Joe Manchin (D-WV) told Breitbart News in an exclusive statement that he plans to support Trump’s border wall funding and that he has voted on multiple occasions to fund a border along America’s southern border.

Sen. Heidi Heitkamp told Breitbart News in an exclusive statement on Thursday that she has “always supported” increased border security and wall funding. The North Dakota Democrat also signaled that she would remain open to the idea of partially funding President Trump’s border wall in the September spending bill. However, it would depend on the parameters of the legislation.

“The devil is always in the details,” Heitkamp told Breitbart News.

In contrast to Sens. Heitkamp and Manchin, Sen. Tester’s office has not responded to multiple requests for comment over whether he plans to support increased border wall funding in the September spending bill. The Montana Democrat’s office also did not respond to inquiries over what alternative methods of border security Sen. Tester would prefer instead of a wall along the southern border, given that he has stated that a border wall might waste taxpayer dollars.

The Federation for American Immigration Reform (FAIR), a leading immigration group, said last year that a “physical barrier on the southern border is a necessity” if the government hopes to secure its southern border.

Rosendale’s campaign released an ad this week, slamming the Montana Democrat for signing up for the Democrats’ “radical immigration agenda.”

In the ad, President Trump charges, “Trump declares, Jon Tester, he signed up for the Democrats’ radical immigration agenda. The Democrats want open borders, which means lots of crime.”

At the beginning of 2018, Tester voted twice to shut down the federal government to force the government to grant amnesty to the Deferred Action for Childhood Arrivals (DACA) illegal aliens.

Rosendale concluded in his statement to Breitbart News, “We need to secure the border and build the wall, we need to end sanctuary cities, deport criminals, and bring law and order back to this country.”