(Reuters) - Republicans unveiled several catchy slogans when they met here to nominate Mitt Romney for president. But one word kept popping up that summarized the shortcomings of their chosen candidate: "humanize."

Though U.S. voters may respect Romney, they don't seem to like him much, and the central mission of the Republican convention was to show the personal side of a candidate who has been reluctant to reveal it himself.

Romney may never beat Democratic President Barack Obama in a popularity contest, but Republicans hope that voters will at least warm to him enough in the final months before the November 6 election that they can turn the focus back to the sluggish economy and Obama's job performance.

Thus Romney, who made hundreds of millions of dollars in the take-no-prisoners world of private equity, spent a good portion of his speech on Thursday night talking about his Mormon faith, his family, and the struggles he faced getting his business off the ground. He entered the convention hall through the crowd, dispensing hugs and handshakes.

"You need to know more about me and about where I will lead our country," said Romney, who has been introducing himself to voters as a presidential candidate on and off for the last five years.

But more often than not, Romney turned personal stories outward to focus on those around him: his parents, his wife, Ann, and the businesses that thrived under Bain Capital's leadership.

Unlike Democratic President Barack Obama, who has written movingly about his struggle to forge an identity as a biracial son of a single mother, Romney still seemed reluctant to give voters a sense of his inner emotional life.

"He was as personal as he's ever going to get. He's not the type of person who's going to sit in a chair with Oprah and pour his heart out," said Tobe Berkovitz, a communications professor at Boston University.

Instead, it fell to others to "humanize" the candidate this week.

Ann Romney described his steady support as she battled cancer and multiple sclerosis. A touching video biography featured photos of a teenage Romney gazing love-struck at Ann, and home movies of him romping with his five young sons.

'A COMPASSIONATE FRIEND'

The most moving portion of the evening on Thursday occurred hours before network television tuned in, as fellow Mormon parishioners talked about how Romney stepped in to help when their children fell seriously ill.

"I know him to be a loving father, a man of faith and a caring, compassionate friend," said Pam Finlayson, a member of Romney's church in Boston.

Republicans in the convention hall said they believed Romney had connected on an emotional level.

"This whole convention was more about telling a personal story about Mitt Romney the person rather than what his policies would be," said Tony Fratto, a Republican strategist who served in the administration of Republican President George W. Bush. "He need to connect with Americans, and I think he accomplished it."

Up to this point, Romney has not been an especially sympathetic figure for voters.

Although he leads Obama by 2 percentage points in the latest Reuters/Ipsos poll, he trails Obama by 20 percentage points on the question of likability.

Perhaps with this in mind, Romney phrased his attacks on Obama more in terms of disappointment than anger.

"I wish President Obama had succeeded because I want America to succeed," Romney said. "But his promises gave way to disappointment and division."

As the presidential campaign heads into the fall, Romney's campaign does not need to make voters fall in love with him - it only needs to make sure Americans are comfortable with him, said Samuel Popkin, author of "The Candidate: What it Takes to Win - and Hold - The White House."

"Think of all the doctors you've really trusted," said Popkin, a professor at the University of California at San Diego. "You need to be comfortable and trust them and think they know what they're doing. They don't have to be the life of the party."