U.S. Rep. Ron Paul and former Sen. Rick Santorum participate in a debate co-sponsored by CNN.

Editor’s Note: Todd Graham is the director of debate at Southern Illinois University. He has coached his teams to national championships and has been honored with the Ross K. Smith National Debate Coach of the Year award. Graham has evaluated presidential debates for five elections and been analyzing the presidential debates for CNN.com’s Opinion section during the 2012 campaign.

Story highlights

Debate coach Todd Graham: As new front-runner, Rick Santorum faced his turn to be grilled

He says ex-senator appeared inconsistent on issues such as No Child Left Behind vote

Ron Paul's attacks on Santorum effective but could have been even sharper, Graham says

Graham: Santorum is lucky there are no more debates before Super Tuesday

CNN  — 

This was Rick Santorum’s first debate with front-runner status. That means it was his time to get grilled like a fine Kansas City steak. And I wouldn’t say he came out of it like a filet.

Even though his rivals missed some opportunities to press their case against the former senator from Pennsylvania, Santorum couldn’t escape the barbecue. It was his old nemesis, Ron Paul, who had the most damning attacks. Perhaps we should have expected Paul, who has been arguing with Santorum ever since the first debates, to be the most prepared. After all, they have been sparring for more than six months. Paul began the debate by calling Santorum a fake. And he didn’t shy away from it.

One issue was the fact that Santorum voted for No Child Left Behind. Paul was arguing that Santorum couldn’t control the deficit and cited the expense of No Child Left Behind as one example. Paul’s best line came after Santorum compared his conservative record to other members of Congress – the Texas lawmaker said the American people are sick of Congress, so it’s a “cop-out” to compare yourself to them. He said Santorum had no credibility since he acted one way while in the Senate but argued for a different policy while running for president.

Todd Graham

I thought this was damning enough, but then later in the debate, Santorum stepped in deeper when he said he voted for No Child Left Behind even though it was against his beliefs, calling politics a team sport and saying he had been supporting President George W. Bush in that vote. I don’t think he understood that he fed right into the critique Paul was making about Santorum’s credibility and sticking with principle. (Did anyone find it ironic that the one word Santorum used to describe himself in the debate was “courage”?)

Paul countered that the idea of “team sport” is the problem with Washington. One’s obligation should be to his or her oath of office and not to the party.

There was another moment when Paul was on the offensive but failed to take full advantage of his position. Paul reminds me of so many debaters I’ve watched over the years who see an opening but don’t quite know what to do with it. Paul correctly noticed a problem with Santorum’s support for Title X, which funds family planning programs, coupled with Santorum’s braggadocio solution of creating and voting for Title XX abstinence programs. To his credit, Paul mentioned that Title XX costs money too and, in his view, also overstepped the bounds of the federal government’s rightful role. But he could have completed the argument with just a bit more thought.

I’ve always loved the “rephrase” in debates. It is an incredibly effective and persuasive tool. I wanted to see Paul rephrase Santorum’s position. Watch how easy it would have been: “Rick Santorum now claims that he voted for one costly and intrusive measure (Title X) but made up for it by introducing another costly and intrusive measure (Title XX). Only in Washington do two wrongs make a right.”

Santorum was in a trap, but Paul didn’t know how to spring the dang thing.

While the attacks weakened Santorum’s debating performance, there were even more missed opportunities to score against him. These Republican presidential debates have demonstrated that it usually takes at least two full debates of being the front-runner before your opponents figure out the most effective attacks.

Think back to Herman Cain and 9-9-9 (seems so long ago), or to Mitt Romney and the South Carolina debates or to Newt Gingrich and the Florida debates. Each time a front-runner was singled out by multiple other candidates over a series of debates, that front-runner faltered. But 9-9-9, “RomneyCare” and moon colonies were all ideas that escaped their first debate critiques before being skewered in a second attempt.

My point is that Santorum is fortunate there aren’t any more debates before Super Tuesday, because I think the other candidates would fare even better.

Santorum had a couple of weaknesses in this debate that weren’t challenged enough.

These include the role of women in combat (where he all but said he would overrule the decisions of the military leaders if he disagreed with them), his vote in support of the “Bridge to Nowhere” (in how many elections will this be an issue?) and his oddly contradictory stance on contraception (he is against it while railing on the negative consequences of teen pregnancy and children born out of wedlock).

On Wednesday night, Santorum was on the defensive, and so he was unable to make his best case for president. Gingrich, Romney and Paul all succeeded because they had strong debates, and they stayed, for the most part, out of the fire.

There’s only one debate left on the schedule, March 19. If it takes place, who will the front-runner be by then? Whoever it is, he will need to be more prepared to debate in my backward-step-pivot-forward technique. The football adage is that defense wins championships, and that could be the case. But it sure doesn’t win any presidential debates.

Follow CNN Opinion on Twitter.

Join the conversation on Facebook.

The opinions expressed in this commentary are solely those of Todd Graham.