Operating Engineers Union Local 150 is making good on its threat to back a Republican primary opponent against House Republican Leader Jim Durkin.

The union local’s president, Jim Sweeney, told me he had about a dozen members in Durkin’s district passing nominating petitions for Burr Ridge Mayor Mickey Straub a couple of weekends ago. Straub is running against Durkin as a Republican. Sweeney said he expected to double that number the following weekend.

Challenging a legislative leader in a primary is just not done. But these are not normal times.

Local 150 led the fight against Bruce Rauner in the 2014 Republican primary and then backed a Libertarian Party candidate against him that fall.

The union’s leadership has fumed as Rauner has pushed his anti-union agenda, and now wants some payback on Durkin for helping to kill their bill to ban the creation of “right to work” zones by local governments. The governor vetoed the bill and the union tried twice to override Rauner without success, mainly because Durkin was able to keep his caucus together.

Since the union blames Durkin they’ll ally themselves with anybody, including Republican activist Dan Proft, if they have to. Proft is backing Straub against Durkin, who he claims isn’t fit to be Leader. But Proft is not exactly known for being a big union supporter.

In fact, according to the Daily Law Bulletin, Proft co-founded the Liberty Justice Center, which, irony of ironies, is representing Lincolnshire against a lawsuit backed by Local 150 over the village’s creation of a local right to work zone – the very event that Local 150’s vetoed bill tried to outlaw. Don’t even try to wrap your mind around all that. You’ll go nuts. This fight is beyond ideology. Sweeney and Proft have a common cause – messing with Durkin – and they’re sticking with that.

Leader Durkin, for his part, took the diplomatic high road, releasing a statement saying: “Our caucus has worked with Local 150 in the past and will continue to work with them, where we can, in the future.”

And, indeed, Local 150 recently sent a mailer praising Rep. Terri Bryant (R-Murphysboro) for her vote to override Gov. Bruce Rauner’s veto of the union’s right to work zone ban.

But you gotta figure Leader Durkin had to be gritting his teeth when he approved that statement. A primary race is a lot like a family fight. And even though Local 150 has a ton of Republican members and has supported Republican candidates in the past, its involvement is undoubtedly seen as outside meddling. The fact that Sweeney lives in Speaker Madigan’s district probably doesn’t help matters much.

The race is already starting to heat up. One of Proft’s newspapers, the West Cook News, published a story a few days ago about Durkin’s law practice, connecting the Leader’s bond work for the City of Berwyn to legislation allowing local governments to tie bond payments directly to revenue they receive from the state. Durkin voted for the securitization legislation, which just recently helped the City of Chicago obtain a “AAA” credit rating on a bond sale. Critics contend the law will allow municipal governments to more easily go into ever-deeper debt and the paper ran a quote from someone calling Durkin’s vote a “horrible conflict of interest.”

The same publication ran another story about a Republican congressional candidate making fun of Durkin’s bill to set up a statewide sexual harassment hotline. “What does it say about Rep. Durkin and his colleagues whom he supposedly leads when he all but admits that an anonymous hotline is required?” said Jeffrey Leef, a River Forest radiologist who is running against Congressman Danny Davis and has supported a universal annual base salary of $30-40,000 (yes, you read that right). “The only submission that Jim Durkin should be making is my order of french fries when he takes his more-appropriate job of cashier at McDonald’s.” Classy.

I’m thinking we’ll see more stuff like that, and not just in obscure publications, but in mailers and other advertising. A fundraising email from September claims the Illinois Policy Institute’s John Tillman, along with the Illinois Opportunity Project’s Proft, Pat Hughes and Matt Besler had already raised $25 million toward a $30 million goal to elect “a ‘Reform Slate’ of candidates to run in House elections across the state to pick up the nine seats Republicans need to gain control of the House and depose Madigan once and for all.” They haven’t yet reported receiving that cash, however.

Rich Miller also publishes Capitol Fax, a daily political newsletter and CapitolFax.com.