Sometimes, one more candidate makes a big difference.

On Monday, City Club of Boise members heard from all four Republican candidates seeking to succeed retiring State Superintendent Tom Luna — and heard some sharp distinctions on the issues.

One reason: John Eynon, a Cottonwood music and drama teacher courting the GOP’s conservative faction, attended Monday’s luncheon forum. Eynon has made opposition to the Idaho Core Standards a centerpiece of his campaign. That makes Eynon something of a foil to the other three candidates in the field: Melba district Superintendent Andy Grover, American Falls principal Randy Jensen, and Mountain Home administrator Sherri Ybarra, who all support the new standards.

And on Monday, that also made for some clear differences in perspective. The result was a debate with a little bit more bite — compared to an informative but a bit more nuanced KIVI TV debate last week, featuring only Grover, Jensen and Ybarra. (Eynon did not attend this debate, held in Nampa, citing a prior commitment at his school.)

The other candidates repeated their more subtle concerns with Common Core: Grover wants to make sure teachers have the tools to implement the new standards; Jensen wants Idaho to fully test the Common Core-based assessments before using them as a yardstick to grade students or schools; Ybarra wants to make sure there are adequate mechanisms for students who lag behind. There was no gray area in Eynon’s critique of Common Core. He labeled it as an “experiment” consuming one-half of the state’s general fund budget.

“(It’s) just more big government,” said Eynon, “and I’m opposed to that.”

Eynon also came out strongly in favor of tapping Idaho’s endowment lands for natural gas development and increased timber harvest, calling this the “low-hanging fruit” that would boost state funding for K-12. He also said he opposed compulsory kindergarten — and he said he didn’t want 3- to 5-year-olds exposed to what awaits them in the public schools by attending pre-K. “We are not a socialist state, and our children are not wards of that state.”

The pre-K comments stirred up a bit of a discussion on Twitter. “(Eynon) doesn’t want pre-k kids exposed to ‘government schools,’” wrote Emily Walton of Boise, one of the 200 or so people at Monday’s forum. “Crazy town.”

Walton, who managed Boise Democratic Rep. Holli Woodings’ 2012 primary campaign, doesn’t exactly fit the profile of Eynon’s supporter base. Or, for that matter, the voter demographic likely to turn out for the GOP’s May 20 closed primary.

The open question is how Eynon’s stances on Common Core, endowment policies and pre-K play in that voting sample — and whether it gives him an opening in a campaign against three opponents who don’t differ too much on these issues.

That answer will come in time — in 15 days, to be precise.

More reading: Clark Corbin’s coverage of Monday’s forum.

Disclosure: As a City Club of Boise board member, I organized Monday’s forum. I also was a panelist on Wednesday’s KIVI debate.