State Auditor Matt Rosendale

(HELENA) Two prominent Republican U.S. senators are backing Montana State Auditor Matt Rosendale in his bid to challenge Democratic Sen. Jon Tester.

Sen. Mike Lee of Utah announced his endorsement of Rosendale Wednesday night, and Sen. Ted Cruz of Texas, a 2016 Republican presidential candidate, followed suit Thursday morning.

Both Cruz and Lee are leaders of the Republican Party’s conservative wing in Congress. In their statements, they called Rosendale a principled conservative leader.

This is the first time sitting members of Congress have announced support for a candidate in Montana’s contested 2018 Republican Senate primary. In addition to Rosendale, five other Republicans have announced their candidacy: businessman Troy Downing of Big Sky, former district court judge Russ Fagg of Billings, state Sen. Al Olszewski of Kalispell, business owner Ron Murray of Belgrade and financial advisor James Dean of Havre.

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Rosendale previously won support from several national conservative groups and from Breitbart News chairman Steve Bannon, President Trump’s former chief strategist.

Tester is running for a third term in the Senate next year. National Republican leaders believe he could be one of the most vulnerable Democratic incumbents in the country.