Editor's note: Todd Graham is the director of debate at Southern Illinois University, Carbondale. 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 analyzed presidential debates for five elections.
(CNN) -- Mitt Romney had another debate Saturday night in which he didn't make many mistakes, was smooth, knowledgeable, even presidential.
It was his worst performance yet. The game has changed, and someone forgot to tell him.
He is behind in national polls, and this time it's serious: His main rival, Newt Gingrich, is polling well not just in Iowa, but also across the country. Saturday night's debate was on a major network, with a wide audience, in the first state in the nation to hold a caucus -- and there is only one more debate before that voting. The conclusion is inescapable. Romney blew it.
Let me reiterate something I've said before (it can't be overstated): Your debating strategy must change based on your position. If the debate team I coach is a heavy favorite in a debate, I coach the debaters to keep doing the same things that made them the favorite. But if we're an underdog, we will approach the debate with an entirely different argumentative strategy.
Mitt Romney is still debating the way he was six months ago. He's debating not to lose instead of debating to win. And that's a mistake, given the rise and potential staying power of Gingrich.
Romney committed three major errors in Saturday evening's debate. And what is maddening is that they were all opportunities for him to differentiate himself from Gingrich -- but he failed each time.
The first error was when George Stephanopoulos directed a possible bonanza question to Romney. He asked Romney if he was more conservative (his potential weakness) and more electable (his potential strength) than Gingrich. Perfect softball. In one answer, Romney could erase doubts about his conservatism for the base of Republican voters and he could talk about how he is the only candidate who can beat Obama (as evidenced in polls).
Romney's answer? Moon mining. Seriously. After starting with some generic answer about the direction of the country, his first specific example was that he was different from Gingrich on moon colonies. "We could start with his idea to have a lunar colony that would mine minerals from the moon. I'm not in favor of spending that kind of money to do that."
That was his "go to" answer. Awful. Romney never mentioned his conservative principles or background, and he never attacked Gingrich on electability. Not even once.
Romney's second mistake was that he was shallow when he should have been on the attack. Gingrich recently said the Palestinians were an "invented" people. While Romney held his own in an exchange on this issue, saying he was not a rhetorical "bomb thrower" who would hurt our allies, he did not take the argument as far as he should have. One of Gingrich's perceived weaknesses is his imprudence, rhetorical and otherwise. Romney could have hammered home an argument that Gingrich would be a poor chief statesman because of his often-inappropriate outspokenness.
Finally, when the other candidates teamed up on both Gingrich and Romney, as they did with health care (Bachmann's new angle of attack for the evening was calling the two "Newt Romney"), Romney needed to immediately separate himself from Gingrich. Why? If Gingrich is leading, and the voters think he and Romney are identical, then why would they vote for Romney? They wouldn't. But Romney didn't ever get the separation he needed. The teamwork was effective, and both Gingrich and Romney were grouped together time and time again. This did not help Romney.
For his part, Gingrich seemed to escape the other candidates' criticism, partly because it was split (some attacks were aimed at Romney), and because the discussion did not stay on one topic for long enough to make Gingrich defend his positions in depth.
He was able to get out his front line of debate answers, and that was good enough to get him by without too much damage. In any form of debate, if you want your attacks to stick, you must stay with them for an extended period of time so you can rebut the answer of the opponent you are attacking. This did not happen last night, and is one of the weaknesses of these presidential debates.
But Gingrich was far from passive, stepping up repeatedly to attack. A favorite line: "I am a Reaganite, I'm proud to be a Reaganite. I will tell the truth even at the risk of causing some confusion, sometimes with the timid." That's what the Republicans are looking for. They want tough conservative talk and someone who can take the fight to Obama. Gingrich behaved as though he was ready and willing to do so. And Romney missed his chance in this debate.
There is only one more debate before the new year and before the voting begins in Iowa. I would suggest Romney take a serious look at changing his approach. Staying the course might feel safe, but it is no longer a winning strategy. Sometimes you risk everything when you refuse to take risks. Does Romney really want to bet the nomination on the hopes that Gingrich will implode? (He really needs to stop betting in these debates, by the way. A $10,000 bet he offered to Perry, over Perry's accusation that he'd excised one of his positions from a later edition of his book, could not have helped him in the heartland.)
Debating not to lose is perhaps the riskiest thing Romney can do at this point.
The opinions expressed in this commentary are solely those of Todd Graham.