Scan the crammed exhibition hall in downtown Atlanta where a beaming Hillary Clinton is on stage selling herself to more than 5,000 cheering Georgia activists and you will know at once that not everyone is ready to buy. Barack Obama's supporters are a little quieter – he is not in town tonight – but they are surely here.
"We know that change is on the way," Mrs Clinton declares in the opening line of a speech that, as it goes on, increasingly borrows from themes practised by Mr Obama. "Are we ready for a change?"
No one can have missed the fact that of the eight men who had escorted her to the microphone, seven were African-Americans, among them John Lewis, a famed Georgia congressman and a hero of the civil rights movement.
Between now and "Super Tuesday", the two candidates left standing in the Democrat nominating contest are left grappling with a three-dimensional jigsaw puzzle. It is all about the constituencies they can count on – of age, race, gender and also geography – and which will deliver the most votes to them.
Here in the Deep South, four states – Georgia, Alabama, Arkansas and Tennessee – all vote next week, offering a booty of 296 convention delegates. That is more, for instance, than the 281 up for grabs in mighty New York. Mr Obama will be counting on doing well here to counter a possible Clinton deluge elsewhere.
That the black vote will help him is not in dispute, in Georgia especially, where, as in South Carolina, Democrat voters will again be majority African-American. Young people are for him. Yet polls here show a tight race. Mrs Clinton has other constituencies to help her here, including women and perhaps white men once with John Edwards. And there is the state's fast-growing Hispanic community.
Having black support may not be enough for Mr Obama therefore, even here. The Democrats believe that in November they can recapture the South – and particularly its white moderates – which defected to the Republican column back in the Reagan years. But are white moderates Obama fans?
If he doesn't win in Georgia on Tuesday, where will he? "The challenge for him is to improve his standing with white voters," said Merle Black, a widely respected political scientist at Emory University here. "The black vote is too small in other states to produce a victory for him. He has to expand his base."
That Mr Obama may be vulnerable even in the Peach State is evidenced by the candidates' schedules. Though absent tonight, he spent the early part of the week here.
And Mrs Clinton is in town because she smells opportunity. This has, in fact, been a two-event day for her. Hours before, in the same Georgia World Congress complex, she addressed a huge convention of southern Baptists.
A champion of the Baptists here is the former President Jimmy Carter. An endorsement by him would surely boost Mr Obama. In comments this week, he almost obliged, but not quite. Now 83, Mr Carter called his campaign "captivating" and "titillating". He added: "I think that Obama will be almost automatically a healing factor in the animosity now and the distrust that relates to our country."
Picking at his chicken wing at the Democratic dinner, Willy Mosley, 45, an African-American who has fought for office in DeKalb County, in suburban Atlanta, thinks that Mr Obama will prevail in Georgia, at least, but not by much. "It will be a fight and it won't be a landslide," he says, but adds that Mr Obama has his ear to the ground and sees him catching ground "by leaps and bounds".
Lynn Roberts, 62, a retired teacher, is sharing her table with Democrat officials from Dawson County, north of the metropolis. She identifies herself as precisely the kind of white swing voter both candidates crave by wearing two buttons on her blouse – for Mr Obama and for Mrs Clinton. She voices a common reservation about the former. "I like him but I wonder if he really has the experience for government."
So what of her table mates – all white middle-aged Deep South Democrats? In a pause between speakers they agree to vote by a show of hands. How many like Mr Obama better than Mrs Clinton and, secondly, how many think he can actually win the state? It is six votes to three in favour of Mr Obama for each question. Ms Roberts abstains both times, but concedes: "Yes, he might very well win Georgia."
Might, not will.
For rolling comment on the US election visit: independent.co.uk/campaign08