Mitt Romney had ample debate practice during the rough-and-tumble Republican primary, besting his GOP rivals in a test run that should have kept him limber for his first debate with President Obama Wednesday.

While Romney's primary performances revealed a steadiness under pressure, the Republican nominee faces a unique challenge going mano-a-mano with an incumbent president on center stage.

Romney was crowned the winner of most Republican debates because he showcased an in-depth knowledge of policy issues, while keeping his cool amid attacks from his conservative challengers.

But Romney also benefited by avoiding no-win confrontations -- an easier task with multiple candidates sharing the limelight -- letting the likes of Rick Perry, Michele Bachmann and Herman Cain stumble into gaffes that snagged the media attention.

In light of that history, some analysts expect a solid showing from Romney during Wednesday's debate but question whether he'll deliver the knockout punch required to gain ground on Obama.

"He was much better in the debates this time around than four years ago," Martin Medhurst, an expert on presidential communication at Baylor University, said. "Is he a great debater? No. Is he going to sweep people off their feet with his eloquence? No. But he's solid."

During the primary, Romney proved he was the smartest kid in the classroom. Now he needs to punctuate his presidential image -- and do so in ways that register with voters.

"He has his awkward moments, but he also has several advantages," said Northeastern University professor Alan Schroeder, who focuses on presidential communication. "He's very efficient. He has a good understanding of the debate dynamics. He seems fully in the moment."

Romney hasn't done a one-on-one debate since he ran for Massachusetts governor a decade ago. In this new setting, he'll look to disarm Obama in a congenial way.

Some conservatives said Romney's showing in the GOP primary proved he's up to the task.

"What he's shown is that he can debate in a number of ways," former Congressional Budget Office Director Douglas Holtz-Eakin said. "The truth is he's proven to be a capable guy. When Obama attacks, Romney should smile and get back to the issues."