SPRINGFIELD, Ill. – GOP gubernatorial candidate Bruce Rauner has warned that the “government union bosses” are trying to “hijack” the Republican primary, and it looks like he’s right.

At a Republican debate earlier this week, the three other GOP gubernatorial candidates lashed out at Rauner – the race’s apparent frontrunner – for saying public employee unions are “immoral” and have a “corrupting influence” on government.

This was an important development, as Rauner has made criticism of public employee unions a central theme of his campaign, the Daily Herald notes.

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State Sen. Kirk Dillard – who was recently endorsed by the state’s largest teachers union – blasted Rauner’s efforts to “demonize” public employee unions, according to the Daily Herald.

“Unions are not inherently bad,” Dillard sniffed.

State Sen. Bill Brady and state Treasurer Dan Rutherford got in on the act and chided Rauner for being so harsh toward the unions.

“I think it’s abusive to use the word ‘immoral,’” Brady said.

Rutherford was less imaginative and settled for calling Rauner’s criticism “inappropriate,” the Daily Herald reports.

Perhaps Brady and Rutherford chose to defend the government union bosses because they’re still hoping to land endorsements (and money and get-out-the-vote help) from some of the other labor groups, including, the Illinois Federation of Teachers – the state’s other major teachers union.

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The other three GOP candidates are talking nice about the unions because they’re looking for every possible advantage against Rauner. Some observers believe Rauner is the strongest Republican candidate, partly because the billionaire has ability to “self-fund” his campaign if need be.

The reason the teacher unions and the other public employee unions are getting involved in the GOP race is even clearer: Gov. Quinn’s campaign is beginning to emit the stink of political death. A recent poll shows each of the four Republicans ahead of the incumbent governor, and the unions are scrambling to find a “Plan B.”

We understand the give-and-take of politics, but it’s still disheartening to see three conservative-ish candidates so willing to climb into bed with the teacher unions and other public labor groups, just to gain a temporary political advantage.

Illinois voters may find that disappointing, too, considering that the only way their state is going to ever get its financial house in order is by adopting some Wisconsin-like reforms of public sector unions.

By choosing to blast Rauner instead of the labor bosses, Dillard, Rutherford and Brady may have inadvertently revealed themselves to citizens as not being up to the task at hand.

The GOP primary is March 18.