The fiscally conservative Club for Growth is endorsing Alaska Senate candidate Dan SullivanDaniel Scott SullivanIcebreaking ships are not America’s top priority in the Arctic Overnight Energy: Senate panel sets Pruitt hearing | Colorado joins California with tougher emissions rules | Court sides with Trump on coal leasing program Pruitt to testify before Senate panel in August MORE (R), giving him a boost in his primary as he seeks to face Sen. Mark BegichMark Peter BegichFormer Alaska senator jumps into governor race Overnight Energy: Trump directs Perry to stop coal plant closures | EPA spent ,560 on customized pens | EPA viewed postcard to Pruitt as a threat Perez creates advisory team for DNC transition MORE (D-Alaska.).

The endorsement marks a shift for the Club, which backed Joe Miller in his race against Sen. Lisa Murkowski (R-Alaska) four years ago.

Their endorsement switch this time could help Sullivan shore up his conservative credentials in the crowded primary against Alaska Lt. Gov. Mead Treadwell (R) and Miller. 

It also might be a sign the deep-pocketed group is looking to be more of a team player in GOP politics this election cycle — having the conservative group close ranks with more establishment Republicans helps elevate Sullivan even more as the GOP front-runner and could help him in his race against Begich.

Sullivan, a former Bush administration official and head of the Alaska Department of Natural Resources, has emerged as the favorite of many establishment Republicans in the race. He also has the support of National Republican Senatorial Committee Vice Chairman Rob Portman (R-Ohio), who is close to Sullivan's brother, and has been outpacing his opponents in a big way in fundraising since he entered the race.

"Dan Sullivan is a fiscal conservative with a stellar track record in Alaska and we strongly endorse him for the United States Senate." said Club for Growth President Chris Chocola in a statement. "Dan has fought for pro-growth tax reform, taken on ObamaCare in court, and beaten back federal overreach by Obama's EPA. In the Senate, Dan Sullivan will continue the fight for economic freedom and we can’t wait to see him help deliver for America the kinds of pro-growth policies he’s already delivered for Alaska."

This is the Club's third Senate endorsement of the cycle, and their mix of helping and fighting the establishment sets them apart in a big way from some of the more rabble-rousing conservative groups. They're targeting Sen. Thad Cochran (R-Miss.) for defeat, but they and establishment Republicans have united behind Rep. Tom Cotton's (R-Ark.) Senate campaign.