Former Alaska Gov. Sarah Palin endorsed Danny Tarkanian for the U.S. Senate in Nevada, an endorsement Palin and Tarkanian provided to Breitbart News exclusively ahead of its public release.

“Danny Tarkanian is a conservative outsider who will support the ‘America First’ policies our nation needs to survive and thrive, including building the border wall, ending sanctuary cities, and finally repealing Obamacare,” Palin said in the statement endorsing Tarkanian, provided exclusively to Breitbart News. “Commonsense Conservatives in Nevada and across America need to unite and help win this critical fight. I strongly endorse Danny Tarkanian for the United States Senate and look forward to helping him win this important election.”

Tarkanian responded by thanking Palin, and pledging to stand up for President Donald Trump in a way that incumbent career politician Sen. Dean Heller (R-NV) has not.

“I thank Governor Palin for her endorsement and appreciate the confidence she has shown in our campaign,” Tarkanian said. “I will hold Dean Heller accountable for turning his back on Nevadans by voting against the repeal of Obamacare and helping Hillary Clinton win Nevada by attacking Donald Trump over and over again.”

Tarkanian’s race against Heller comes as Heller, a far-outside-the-mainstream establishment Republican, has not stood with President Trump on most issues. For instance, according to the Las Vegas Review-Journal, Heller “bragged about his dissent against the Republican-backed health reform bills” and he “stated he would continue to uphold” support for former President Barack Obama’s Deferred Action for Childhood Arrivals (DACA) executive amnesty for illegal alien youths.

In addition, Heller announced his opposition to the idea that President Trump would pardon Arizona’s former Maricopa County Sheriff Joe Arpaio.

“I’m not from Arizona, I see this from a distance and I read it, so on, so forth,” Heller said of Trump’s position on Arpaio, per the Las Vegas Review-Journal. “But I just want to make the point that the president was going to come to Phoenix yesterday and pardon him, and chose not to do so. And I certainly hope that’s the position that he has in the future.”

When Trump was in Phoenix on Tuesday night, he hinted at a looming pardon he plans to grant Sheriff Joe. “You know what, I’ll make a prediction: I think he’s going to be just fine,” Trump said in the Phoenix speech. “OK? But I won’t do it tonight, because I don’t want to cause any controversy.”

Unlike Heller, though, Tarkanian supports the president when it comes to Arpaio.

“The President had very good things to say about Sheriff Joe Arpaio last night (Tuesday) in Arizona and if he makes the decision to pardon Arpaio, then I will strongly endorse and support that decision. It is wrong for Dean Heller to publicly oppose the President’s action even before the President has formally announced his decision,” Tarkanian said per local news reports.

Heller also, per CNN, announced after the Senate failed to repeal and replace Obamacare that he was “pleased” with how it turned out.

“I wake up every morning trying to figure out what’s best for the state of Nevada, what can I do for Nevada families. And obviously we got in the middle of this health care battle and I feel real pleased at the way this thing turned out and we’re turning the page now to tax reform,” Heller said after Sen. John McCain (R-AZ) switched to voting against efforts to repeal Obamacare.

Polling data on the race suggests that Tarkanian has a chance to topple Heller in Nevada, should he gain momentum moving into the next several months. Senate Majority Leader Mitch McConnell, however, is likely to fight as hard as he can to save Heller—but endorsements from major national conservative figures like Palin open the door to a potential upset.

Palin’s endorsement of Trump in Iowa before the caucuses last year was critical in solidifying the president’s position with conservatives. Trump came in second in Iowa’s caucuses to Sen. Ted Cruz (R-TX) but went on to win the primaries in New Hampshire and South Carolina and then stormed his way to the GOP nomination and then the presidency.