Romney, the former Massachusetts governor who leads in the early polls and fundraising efforts, had a surprisingly easy two hours. He looked calm and steady, criticizing Obama on the economy and health care while rarely being forced on the defensive despite some well-known vulnerabilities of his own.
"Every one of these people on stage would be a better president than President Obama," Romney said during the debate.
That was high praise for little-known candidate Herman Cain, libertarian hero Ron Paul and former Sen. Rick Santorum, who badly lost his last re-election bid in Pennsylvania. It also reflected how friendly everyone had been to Romney.
The seven GOP candidates seemed more eager to introduce themselves to voters in the televised event than to start ripping each other. They rarely differed on major policies.
Former Minnesota Gov. Tim Pawlenty, who coined the phrase "Obamneycare " over the weekend, was far less aggressive with Romney standing at his side, while Romney attacked the plan he supposedly inspired.
"If I'm elected president, I will repeal Obamacare," Romney said.
But the difference between Romney's universal health care plan and the president's is one he'll likely be asked to explain.
If any candidate had nearly as pleasant an evening as Romney, it was Rep. Michele Bachmann of Minnesota. She made maximum use of CNN's live telecast to announce she was formally entering the race. And she showed a feisty but folksy style, perhaps grabbing an audience that many once thought would go to Sarah Palin, who was not present.
The Associated Press contributed to this report.