Idaho’s Republican primary usually exposes splits between the party’s hardline and mainstream factions.

This year, those fault lines might be even more pronounced.

A quick look at candidates’ sunshine reports shows that legislative incumbents — and the Idaho Freedom Foundation and its Statehouse allies — are both wagering heavily on the spring primary. And with good reason. The outcomes from the primary could tilt the balance of power in a divided House Republican caucus.

Let’s first look at some of the donors, and who they are supporting:

Scott Bedke. Unopposed, again, in his 2020 re-election bid, the House speaker can use his money to support other House Republicans. He has contributed $12,000 to House incumbents seeking reelection. That list includes Rep. Britt Raybould of Rexburg, facing former state Rep. Ronald Nate, also of Rexburg; and Rep. Jerald Raymond of Menan, facing former state Rep. Karey Hanks of St. Anthony.

Chuck Winder. The Senate majority leader also has been active in a few key Senate primaries. He has supported Sens. Steven Thayn of Emmett and Fred Martin of Boise, and candidates in contested open races: Kevin Cook of Idaho Falls; Douglas Ricks of Rexburg; and Brenda Richards of Murphy.

The Senate retirees. It’s going to be a new-look Senate, with President Pro Tem Brent Hill, Education Committee Chairman Dean Mortimer and Transportation Committee Chairman Bert Brackett among the retirees. All three have been active campaign contributors, and are endorsing candidates who are looking to replace them. Hill supports Ricks, Mortimer backs Cook and Brackett supports Richards.

Frank VanderSloot. The billionaire CEO of Idaho Falls-based Melaleuca has never been bashful about throwing big dollars into a campaign, and he is feuding publicly with the Freedom Foundation. He is supporting Raymond and Bonneville County Commissioner Dave Radford of Ammon, who is challenging Rep. Chad Christensen, also of Ammon.

Tom Luna. The former state schools superintendent is backing Thayn and Kirk Adams, a Middleton school trustee challenging Rep. Tammy Nichols of Middleton.

The Freedom Foundation. While the conservative group does not endorse candidates directly, board members Brent Regan, Doyle Beck and Bryan Smith have contributed more than $21,000 to legislative candidates. Beneficiaries include Rep. Bryan Zollinger, R-Idaho Falls, Smith’s legal partner; Adam Frugoli of Idaho Falls, a candidate for Mortimer’s Senate seat; Christensen; and Nate.

House conservatives. Rep. Heather Scott, R-Blanchard, is backing Nate and Rep. Christy Zito of Hammett, a Senate candidate. Rep. Judy Boyle, R-Midvale, is another Zito backer. House Majority Leader Mike Moyle, R-Star, is backing Rep. Dorothy Moon, R-Stanley. Rep. Brent Crane, R-Nampa, is backing Nate and Rep. Julianne Young of Blackfoot.

Branden Durst. The former legislator — who represented Southeast Boise as a Democrat — contributed to Zollinger and Zito, and made an in-kind donation to Randy Jackson, a GOP House candidate in Nampa.

Who’s raised what?

Here’s a look at fundraising totals in some GOP primaries:

District 8, Senate. Steven Thayn, Emmett (incumbent): Raised $10,450. Marla Lawson, Lowman: Raised $4,124.

District 8, House Seat B. LaVerne Sessions, Salmon: Raised $23,540. Dorothy Moon, Stanley (incumbent): Raised $15,293.

District 9, House Seat A. Ryan Kerby, New Plymouth (incumbent): Raised $17,994. Jim Smith, Fruitland. Raised $5,460.

District 11, House Seat B. Tammy Nichols, Middleton (incumbent): Raised $11,650. Kirk Adams, Middleton. Raised $8,765.

District 15, Senate. Fred Martin, Boise (incumbent): Raised $20,585. Sarah Clendenon, Boise: Raised $745.

District 23, Senate. Brenda Richards, Murphy: Raised $27,290. Christy Zito, Hammett (House member, running for Senate): Raised $17,159.

District 30, Senate. Adam Frugoli, Idaho Falls: Raised $46,669 (includes $25,000 in loans to campaign). Kevin Cook, Idaho Falls: Raised $30,887.

District 31, House Seat B. Julianne Young, Blackfoot (incumbent): Raised $23,543. Donavan Harrington, Blackfoot: Raised $12,271 (includes $8,834 in loans to campaign).

District 32, House Seat B. Dave Radford, Ammon: Raised $30,200. Chad Christensen, Ammon (incumbent): Raised $14,317.

District 33, House Seat B. Bryan Zollinger, Idaho Falls (incumbent): Raised $21,138. Marco Erickson, Idaho Falls: Raised $16,026.

District 34, Senate. Douglas Ricks, Rexburg (House member, running for Senate): Raised $17,761. Jacob Householder, Rexburg: Raised $4,449.

District 34, House Seat B. Britt Raybould, Rexburg (incumbent): Raised $33,824. Ron Nate, Rexburg. Raised $17,323.

District 35, House Seat A. Jerald Raymond, Menan (incumbent): Raised $19,250. Karey Hanks, St. Anthony: Raised $15,870.

The election ground rules

This spring’s primary is all vote-by-mail. If you haven’t requested a ballot yet, you must contact your county clerk or the secretary of state’s office by Tuesday. Ballots must be received by June 2. Details here.

More reading: From the Post Register’s Nathan Brown, more about the ideological divide in Eastern Idaho, and a campaign finance complaint.