NORMALLY, A political challenger is at a disadvantage, running against a known quantity. But this year, known quantities have some explaining to do, if they are S.C. legislators.

As the June 8 primary approaches, the onus is on them to disassociate themselves from the following recent outrages:

The House underfunding education by hundreds of millions of dollars; the collapse of restructuring in the Senate; the abominable Life Sciences Christmas-tree bill; the complete avoidance of comprehensive tax reform; the refusal to consider a cigarette tax increase; the House’s embrace of the governor’s income tax cut even as basic services deteriorate to dangerous levels; the Senate’s refusal (and I blame the whole Senate, for letting a feckless minority get away with it) to save lives with primary enforcement of our seat belt law. To name a few.

Of course, not every incumbent is to blame. So as we have begun the process of endorsement interviews in recent days, the choices have not been simple.

For example, consider the two men seeking the Republican nomination for House District 89 in Lexington County.

At first glance, challenger Ashley Cannon is someone we might dismiss as promising, but in need of more life experience. At 26, he’s been out of college three years, teaching history at White Knoll Middle School.

But things being as they are, we listened to him carefully. And we liked what we heard. A lot.

He’s running because he understands that education is Job One in South Carolina, the key to everything else, and “this Legislature is not going to get the job done.” Further, having grown up on a tobacco farm near Turbeville, he understands that the poor quality of underfunded public schools in rural areas is our biggest educational challenge.

He sees the need for comprehensive tax reform, and is intrigued by the possibilities in the Quinn-Sheheen bill.

He fully supports Gov. Mark Sanford’s restructuring efforts, and opposes his irresponsible income tax cut. He is particularly distressed that the governor just doesn’t get it on public schools.

“Education is like defense at the national level,” he said. “I would not vote for somebody who’s weak on defense on the national level. And I will not vote for somebody who’s weak on education at the state level.”

He supports raising the cigarette tax, even though that doesn’t play well where he comes from. He has never signed a “no-new-taxes” pledge, and never will.

His biggest beef with most lawmakers is that they don’t struggle with issues — they vote the party line, and toddle on home to an early bed.

“I’m a Republican,” he says, the product of an evangelical Christian home “with both parents.” He loves his party. But when asked about the importance of party loyalty, he says, “I think that’s something we need less of,” to the extent that it leads to a herd mentality. As a history teacher, he’s a huge fan of John Adams, a man of principle who steered a sensible, moderate course between the extremists of his own party and the opposition.

On the downside, he not only opposes primary enforcement of the seat belt law, but thinks the issue could be settled by public referendum — an inconsistency with his stated belief in representative democracy. He needs to struggle with that one a little more.

But overall, we were so impressed with him that we told each other that two-term incumbent Kenny Bingham, 41, would have to do some fast talking.

Well, he did. And as he talked, we realized we needed to hear him talk some more. And we saw, as always, both the good and the bad of incumbency. And sometimes good and bad were manifest in the same characteristic.

For instance, Mr. Bingham, a civil engineer by trade, takes a pragmatic approach to legislating.

He acknowledges that he generally votes with the majority, even when he’s not entirely happy with the bill. He’s learned — through experience — that in the S.C. House, things are greased by the time they hit the floor, so the place to have an effect is in subcommittee. He strives to make positive changes at that level. If he fails, he sees little point in making a quixotic gesture on the final vote. That, he knows, will cost him when he needs support on something worthwhile later.

Mr. Cannon accuses him of voting slavishly with the leadership. But Mr. Bingham is quick to point out that he can stand against the crowd. He did so on the Life Sciences bill, not only voting against the polluted version, but supporting the governor’s veto. He was one of the few.

As a former Lexington District 2 trustee, he at least talks the talk on education, even though he voted for the House budget. And he understands the need for equity in the rural areas.

He not only favors comprehensive tax reform, he is one of the small group that drafted the Quinn-Sheheen bill.

He opposes the governor on tax credits for sending kids to private schools. He supports public school choice, and has experience implementing it.

He signed a “no-new-taxes” pledge once, but won’t do it again.

He voted for primary enforcement of seat belts.

That’s the good stuff. On the bad side, he favors spending caps, which can undermine the integrity of representative democracy as much as tax pledges. He is suspicious of critical elements of restructuring. He needs convincing on the cigarette tax, and he wants no additional funding for Medicaid without “reform” — which you might recognize as the House leadership’s party line.

There is a delicate balance sometimes between a strategic approach to effectiveness and compromising oneself excessively. Mr. Bingham seems to be on the cusp of that dichotomy.

So do you go with youth, energy, potential and a lot of good answers, or do you go with pragmatic experience and some good answers, coupled with actually having done some good things? Or at least having taken a courageous stand or two.

Where we’ll end up, I don’t know. But our guiding consideration, in this and all races, will be this: Which candidate will do more in the long run to move South Carolina forward?

Write to Mr. Warthen at bwarthen@thestate.com.