Ros Atkins presented the first part of the journey, travelling all the way from Los Angeles to Dallas.
In this section he visits the casinos of Las Vegas, a biker and a gun club in Arizona.
Part 6: Shooting lesson
The Phoenix Cardinals are hosting the Miami Dolphins this weekend, and so is the hotel we're staying in.
Chicago Bears superstar William Perry was called the refrigerator in the 80s, and all together these guys certainly bear a passing resemblance to the freezer section of the local Walmart.
They are massive, and perhaps more surprisingly, so are their fans.
Arriving at the hotel, the first thing that struck me was the good natured exchanges between two sets of supporters.
Of course this happens the world over, but I suppose I'm noticing it more because on this trip so far the two sides of America don't seem to be talking.
Every day, I keep hearing how far apart people are. It's not that people don't agree, it's the despair and sometimes disdain they clearly feel about each other and their views .
My latest lesson in this was our visit to the .
We pulled off the highway to stop at the range they use to practice. Greeting us off the bus was a lady called Carol. She looked fantastic.
Her glossy grey hair ran half way down her back, and she wore a long black cowgirl's skirt with an equally flamboyant shirt. She also had a gun tucked into a holster... In fact so did everyone.
They took us into their clubhouse for a sandwich and soda, and there we talked.
Me and my colleagues with our microphones and leads, the women with their pistols, bullets and cell-phones round their waists.
The time had come for my lesson and Carol and I walked out onto the range. It was a surreal scene.
The sky blazed red and orange with the sun's last light, and the snap and crackle of gun fire echoed all around.
"I'm nervous," I told Carol. "I've never fired a gun before."
"That's okay," she replied. "The first time I did it I cried."
As I pushed a magazine of 10 bullets into the shiny chrome pistol in my hand, I wanted to know why Carol and her friends are so worried about Barack Obama.
"He doesn't get us," she fired back. "He doesn't understand what generations of our people went through, and he doesn't want to learn. America was made by the gun."
I fired my first shot, and felt marginally more relaxed. But the dead weight of the gun in my hand still didn't feel right.
Carol carries a gun all the time. "Is that about security?" I asked.
She looked at me straight, her eyes wide with emotion.
"It's not just that," she said. "I carry my gun because it's my constitutional right. I wish they'd understand how important that it is to us."
End of Section
Part 5: On Route 66
I'm up the front of the bus with our driver Bo and we're heading away from Las Vegas on none other than Route 66 - and while getting your kicks recording a radio piece may not be the most rock'n'roll behaviour, it'll do for me.
Ros spoke to the Route 66 riders at the Phoenix Grill
We've got the Temptations on the stereo, have just crossed Rattlesnake River, the first cactuses and motels of the trip have been spotted - and the pale greens and browns of the Arizona desert hills are all around us.
This is classic America- the way we imagine it was years back, and how we've seen it on the silver screen.
But while it may look and feel familiar, I've spent lunch hearing how things have changed.
Kingman is a small Arizonan town laid out along the highway, and is home to a wonderful group of genial retirees who belong to the Route 66 Riders Club.
They wear matching red shirts, jeans and boots and like to see their country from the seat of a Harley or a Honda Goldwing. And having just taken a spin on the back of one, it's not hard to see why.
Dave moved down from Michigan when he finished working in the car industry. "The kids they want it all," he told me, "and I know they do work hard, but they don't get that community matters too.They're too busy to realise. We used to look after each other much better." The others nodded.
Lucy continued. 鈥榃e've started to think we can have everything, but we can't. We can't buy everything we want, can't fix every problem in the world that we choose. Maybe at the moment Americans are finding that out the hard way', she said softly.
"But you seem so happy here,' I told them. Would a new President lift your mood about America?
"You bet," they chimed back laughing. We've just got to straighten some things out, they all agreed. "Let's hope it's John McCain doing it," added Dave.
Those saying America's famous optimism has disappeared may be jumping the gun, and the same is probably true for Barack Obama's presidential hopes. But it is beginning to cross people's minds.
While it was once his election to lose it's now John McCain's. And he represents this state in the Senate.
We're heading to Phoenix to find out what the new front-runner is all about.
End of Section
Part 4: Losing in Las Vegas
I'm writing this amid the din of bleeps, rings, chinks and chimes.
Outside another blue sky day is bathing the Nevada desert in light, but you wouldn't know it in this gaming hall. It's chilly, there are no windows or clocks and the air has a really strange taste thanks to the cigarette smoke and the hard-working air-con.
Around me are attention-seeking slot machines, and just over there is the 鈥榳inners wall of fame' with a framed picture of a lady called Rose with a pile of dollars in her arms.
But not everyone is winning in Las Vegas - and while the folks here will lose a few hundred bucks at worst, I'm just back from meeting two people who've lost far more.
Brian's an estate agent, with a wife, two kids and an effervescent demeanour.
A year ago he owned three houses - one for his family, and the other two were done up nicely and ready to sell.
Except they didn't - not at the price he wanted, not at the price he dropped to, not at the price his bank named. He lost them all, and now has a credit rating so bad he can't even get a cell phone.
"Who do you blame?", I asked Brian. "No-one," he replied. "I tried to take advantage of a situation, and it didn't work out," he added, with the air of a man who badly wished he hadn't.
Danielle's a book-keeper and has lost $200,000.
She bought knowing she'd have to refinance in two years - but despite never missing a beat with her mortgage, no-one would do it. She sold up at a cut price before the bank took her home.
"What do you want your next president to do about this?" I asked them both. Danielle was adamant. "Those banks suck - we've got to stop them just pulling the rug from under us."
And Brian? "I'd just like a loan," he said, with a rueful smile.