Sen. Rand Paul (R-KY) endorsed Montana rancher and state auditor Matt Rosendale in a statement on Monday to challenge Sen. Jon Tester (D-MT) in the 2018 Senate midterm election.

“Matt Rosendale is the type of fearless defender of liberty I want fighting by my side in the Senate,” Paul said. “Matt has proven himself a bold defender of our constitutional rights and he will make an excellent addition to the Senate.”

Rosendale said in his statement that he was deeply honored to earn Sen. Paul’s support and pledged to stand with Sen. Paul to advocate for civil liberties and a limited government.

Rosendale said, “I am deeply honored to have Senator Paul’s support. I will stand with Rand as an unwavering advocate for civil liberties and limited federal government. We need more senators like Rand Paul, who mean business and have the backbone to stand up to the D.C. status quo.”

“Supporters of liberty of all types must band together to defeat Jon Tester, who has embraced the worst that Washington, D.C., has to offer. It’s time to elect a serious defender of our freedoms to the Senate who means business,” Rosendale added.

Matt Rosendale remains the sole Montana Republican primary candidate to have current members of the U.S. Senate endorse his campaign; well over 30 Montana elected officials have also endorsed Rosendale.

The Citizens United Political Victory Fund (CUPVF) and the affiliated Political Action Committee (PAC) of Citizens United endorsed Rosendale in December. The pro-Donald Trump super PAC the Great America Alliance also endorsed Rosendale for U.S. Senate.

Sen. Ted Cruz (R-TX) and Sen. Mike Lee (R-UT) have both endorsed Rosendale to challenge Sen. Tester in the 2018 Senate midterm election.

Sen. Cruz said in a statement, “Matt Rosendale has fought hard to shrink government and preserve liberty for Montana residents, during his time in the state legislature and more recently as a state auditor. It’s time to let Matt take that fight to Washington, we need strong conservative reinforcements in the Senate.”

Citizens United President David Bossie charged in a statement in December, “Commissioner Rosendale supports the same common sense conservative reform agenda that millions and millions of Americans support, such as enforcing immigration laws, ending sanctuary cities and enacting pro-growth tax reform to grow our economy and create jobs. I urge all Republican primary voters in Montana to support conservative outsider Matt Rosendale for the United States Senate.”