TAMPA, Florida — Republicans overwhelmingly nominated Mitt Romney and running mate Paul Ryan to challenge President Barack Obama, painting a gauzy portrait of their candidate, playing to the deep economic anxiety of US voters and promising to end what they called Obama's “era of absentee leadership.” With only fleeting signs of the concerns many once expressed about Romney's conservative credentials, delegates rocked the convention hall Tuesday night with enthusiasm for the multi-millionaire former Massachusetts governor, ending his yearslong quest for the party's top honor. The Republican festival played out against a backdrop of polling that shows the race a dead even. Voters say they trust Romney more on economic issues but find Obama the more likable candidate. Keynote speaker Chris Christie, the governor of New Jersey, propelled Romney toward the Nov. 6 election with a characteristically blunt message. “It's time to end this era of absentee leadership in the Oval Office and send real leaders to the White House,” Christie thundered. “Mitt Romney will tell us the hard truths we need to hear to put us back on the path to growth and create good paying private sector jobs again.” Republican exuberance was tempered as Hurricane Isaac hit the southern Louisiana coast just as the evening festivities began, driving a wall of water nearly 11 feet (3 meters) high inland before heading on to New Orleans. That storied city is still recovering from Hurricane Katrina that brought devastation with it exactly seven years ago. The slow federal response to the storm that killed 1,800 people sent former president George W. Bush's presidency into a permanent downward political spiral. As the convention's first full day built toward a crescendo, Romney's wife, Ann, brought a message aimed toward women voters, speaking lovingly of the candidate's virtues as husband and father. Her mission was to humanize Romney, who has been painted by the Obama campaign as a hard-hearted business titan and out of touch with the difficult lives of average Americans. She lovingly talked of her 43-year marriage, noting her own experiences battling muscular sclerosis and breast cancer. She spoke about the struggles of working families: “If you listen carefully, you'll hear the women sighing a little bit more than the men. It's how it is, isn't it? It's the moms who always have to work a little harder, to make everything right.” Her mission was clear: To soften the image of a man who remains a mystery to most Americans and who consistently lags behind Obama among women voters in polls. In the Obama-Romney contest, voters face a clear-cut clash of ideologies. Romney, more conservative on social issues such as gay marriage and abortion, favors cutting taxes, slashing the government and repealing Obama's signature health care overhaul — even though it was modeled after one of his own programs as governor. Obama is liberal on social issues, wants to raise taxes on the wealthiest Americans and sees government as a potential force for good. — AP