He will look out over a convention hall alive with partisan enthusiasm and possibility — the Texans under their matching cowboy hats, the West Virginians in their miner’s caps, the Massachusetts delegation enjoying its rare moment in the Republican sun.

It will be, for Romney, both the culmination of everything he has worked for and a way station on the path to his ultimate quarry: becoming president of the United States. He’s arrived here through diligent preparation, good fortune, and burning ambition, eager to lead his party toward November on his economic message.

“Everyone who has been involved in Governor Romney’s life over the years feels the weight of this moment,” said Kerry Healey, Romney’s lieutenant governor and one of Thursday’s featured speakers.

A frenzied convention hall in Tampa, though, is hardly a nation. So while Thursday’s anointing indeed represents a political triumph for Mitt Romney it is also fraught with risk. To name just one: Can the modern Republican Party, with its increasingly conservative bent, successfully court middle-of-the-road voters?

A national Washington Post/ABC News poll released this week found that 51 percent of independent voters — an important constituency for any winning campaign — said they viewed Romney unfavorably.

Just 31 percent of them said they had a positive impression. Democrats noted gleefully that those are the lowest popularity numbers of any major-party nominee in nearly three decades.

That helps explain why Republican delegates and activists in Tampa want Romney, with many TV viewers tuning in for the first time, to use the opportunity to burnish his personal brand by sharing his life with the country.

“Thursday night will be his night to shine here,” said Lisa Shin, a 32-year-old Republican activist and alternate delegate from Washington state.

Shin hopes Romney can show charisma and excitement, which she said he hasn’t always been able to do in this campaign. “People want to like somebody. They want to be excited about somebody.”

Who bears responsibility for Romney’s failure to connect with voters? It depends whom you ask. Some blame Romney himself; others blame President Obama and his image-makers for sullying Romney’s name and the media’s complicity in that.

“There are a lot of people who do have this elitist view of him,” said Jeff Wasden, 48, the owner of an apparel and uniform company from Highlands Ranch, Colo.

That’s a misleading portrait of someone who has built his own success, Wasden believes, and tonight is Romney’s chance to rip it up.

“It’s important for people to get to know him and that story,” Wasden said. “America needs to know Mitt.”

This work of “humanizing” Romney began Tuesday night, with Ann Romney’s well-received address extolling her husband’s capacity for love and commitment. That work continues Thursday leading up to Romney’s speech, when a parade of people from his life — from the Mormon church, from his administration as Massachusetts governor, and from the Olympics — will testify to his character, leadership, and experience.

Grant Bennett, a longtime friend of the Romney family who, like Romney, has held local leadership positions in the Church of Jesus Christ of Latter-day Saints, is likely to speak to Romney’s heart and his long service on behalf of fellow Mormons. Staples founder Tom Stemberg will surely focus on the positive aspects of Romney’s tenure as head of Bain Capital, which helped launch the worldwide office-supply chain. Former Olympians Michael Eruzione, Derek Parra, and Kim Rhode are expected to celebrate Romney’s role in rescuing the 2002 Winter Olympics. Healey will praise Romney the governor.

Beyond opening up about his life, Romney faces the tall challenge of speaking to several audiences at once.

He must inspire conservatives to get out and work for him; appeal to centrists turned off by the Republicans’ rightward tack; reassure moderate women who object to the party’s hard line on abortion; and win over Hispanics irked by his harsh immigration rhetoric during the primaries.