The hall erupted in cheers when Romney strolled on stage and shared a hug and kiss with his wife of more than 40 years.
"This man will not fail. This man will not let us down," Mrs. Romney said in a prime-time speech that sounded at times like a heart-to-heart talk among women and at times like a testimonial to her husband's little-known softer side.
"It's the moms who always have to work harder, to make everything right," she said. And she vouched firmly for her husband, who lags behind Obama in surveys among women voters: "You can trust Mitt. He loves America."
Earlier, the Romneys watched on television at a hotel suite across the street from the convention hall as delegates sealed his hard-won victories in the primaries and caucuses of last winter. They ended the evening together in a VIP box just above the convention floor.
To send Romney and ticketmate Paul Ryan into the fall campaign, the convention quickly approved a conservative platform that calls for tax cuts — not government spending — to stimulate the economy at a time of sluggish growth and 8.3 percent unemployment.
Republican mockery of Obama began almost instantly from the podium at a convention postponed once and dogged still by Hurricane Isaac. The Democratic president has "never run a company. He hasn't even run a garage sale or seen the inside of a lemonade stand," declared Reince Priebus, chairman of the Republican Party.
More than eight hours in length, the session inside the Republicans' red-white-and-blue-themed convention hall passed up no opportunity to broaden Romney's appeal. Speakers included Hispanic candidates for office; former Rep. Artur Davis, a one-time Democrat and member of the Congressional Black Caucus; businessmen and women and former Sen. Rick Santorum of Pennsylvania, Romney's most persistent, conservative nemesis in the nominating campaign.
