"The days of re-launching yourself this late are over," says Democratic consultant Mary Anne Marsh, principal at Dewey Square Group. "You're reinforcing images, not reinventing them."
Clinton's 1992 convention received eight hours of live network coverage — a fraction of the 35-plus hours for conventions 20 years earlier, but more than twice the time given to conventions in 2004 and 2008.
Highly interested viewers will be able to watch the entire convention program on cable news channels, C-SPAN, and live streaming. But they are most likely to have already made up their mind about Romney. Few of the country's remaining persuadable voters will seek out coverage.
That gives Romney very few opportu-nities to drive home any message about himself.
It can still be done, at least to some extent, if correctly targeted.
In 2008, Obama spoke by video link to his wife and children, who were standing on the convention stage. The adorable exchange was part of a successful attempt to portray the country's first black nominee as a typical, relatable family man.
McCain, on the other hand, used his introduction to re-emphasize his heroism in Vietnam.
In 2004, networks carried a powerful video (narrated by the stentorian voice of Fred Thompson) about Bush's response to 9/11, which perfectly stirred the emotions the Bush team was looking for in holding that year's convention in New York.
John Kerry tried to evoke his own Vietnam service at that year's Democratic convention, most famously by opening his speech with "reporting for duty" and a salute. That didn't work out so well; it was too late in the campaign to start selling that image of the candidate.
"You can't change people's opinions of you overnight," Domenech says. "It's like a down-on-their-luck music star trying to change people's impressions by hosting the MTV awards. It's going to backfire."
So what can Romney do with his convention, to make voters feel at least a little more positive about him?
Gonzales suspects that the campaign will make some effort to "soften his image," perhaps through appearances by Ann Romney and various children and grandchildren.
Others, including Baker and Domenech, advise him to focus on the turnaround-artist theme that has long been Romney's selling point (and title of his first book).
"Tell stories that are not glowing stories about how great he is, but about his accomplishments," Domenech says. "A bad situation, where Romney came in the door and turned it around."
But others are skeptical of both the family and turnaround approach as too backward-looking, and too remote from people's problems — and Washington's.
Romney would be better off, they say, talking about those problems, and his solutions. Domke thinks Romney would be better served releasing his inner wonk — the "Mr. Fix-It" PowerPoint presidential candidate who briefly emerged in front of a whiteboard last week.
"It would blow a lot of minds in the media," Domke says. But viewers might conclude: " 'He doesn't have much of a personality, but he does sound like he has a better plan.' "
That might be as high as Romney can hope to aim. And if he wants to narrow that likability gap, it will need to be by knocking Obama down to his own level.
David S. Bernstein can be reached at email@example.com. Follow him on Twitter @dbernstein.