Ros Atkins presented the first part of the journey, travelling all the way from Los Angeles to Dallas.
Here he reflects on the final section of his trip, from Albuquerque to Dallas.
Part 13: Ros' wrap
My time on the bus ends here in Dallas, so it's time for a little reflection.
Barack Obama says he is tired of hearing about two Americas - but I'm afraid I'm going to disappoint him.
Whether I've been listening to Democrats on Venice Beach, or Republicans at a gun club in Arizona, there's been a real fear of and disdain for the other side.
"Sarah Palin's a fantastic vice president in waiting"; "Christians should support abortion and gay marriage" - these aren't treated as valid opinions, but often as nonsense.
I wondered if George Bush had caused this polarisation - not deliberately, but because he divides opinion like no other.
But he is going, and the divisions do not seem to be.
When in New Mexico, I asked an Obama campaigner how she'll feel if he loses. "Oh, I'm sure the hope will turn to hate," she replied matter-of-factly. I can easily believe it.
There's an organisation called Divided We Fail which wants more communal and non-partisan policies.
And this seems to me the real decision Americans have to make.
Do they want to share responsibility for caring for the sick? For helping hurricane-ravaged towns? For getting more done in Washington? For getting from A to B?
The answer from many people is a passionate yes. Many others, though, put their convictions and commitment to personal responsibility above all else.
Community versus the individual. Partisan versus non-partisan. These are timeless political debates given a striking and fascinating immediacy by Americans.
One quick story to end with.
A Republican was explaining to me the different Christian factions within his party. "Wouldn't all this be easier if you just left the Bible out of it?" I joked with him.
"Probably would," he replied, "but then we'd be liberals and we can't do that."
So that's me done. When Governor Bill Richardson dropped out of the democratic primaries he had what he called a period of decompression. I can feel one of those coming on myself.
The 91Èȱ¬'s World Affairs Correspondent, , is now taking over. Over to you Allan...
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Part 12: Pride and politics
I'm at Gay Pride in Dallas, Texas, and it's getting busier and busier all the time.
As the parade ends, people into the park where I'm sitting. There's the usual variety of styles that veterans of Gay Pride events come to expect: several men wearing little apart from very tight swimming shorts; a guy with a leather thong and jacket; and there are definitely more white vests than your average day in the park.
So far so predictable.
But this event is dealing a blow to any assumptions we may make about the politics of being gay: nearby is the gazebo of the Log Cabin Republicans.
Most are wearing tight t-shirts with "McCain for president" written across the front, and Sarah Palin badges on their pecs.
"How does this work?" I asked them earlier. "You're supporting a man who opposes gay marriage."
"That's true - but look: I’m an American first, a Republican second, and a gay man third," David replied.
"I believe in small government and keeping our country safe from terrorism – that's more important right now. Gay rights we'll get anyhow, if we keep chipping away."
Ranil joined our conversation. His t-shirt read "Republicans for gay equality. Vote McCain."
"Did you hear our convention? There wasn't a single bit of anti-gay rhetoric." Ranil insisted.
"Things are changing, give them time. This election is about the economy and national security and so it should be."
A little later, I met Russell, a Democrat. "We're the new blacks," he said angrily. "It's taken them 50 years to get this close to the presidency, and we're way behind.
"We need Obama, we need to sort out our rights now."
It was fascinating. They all want the same thing, but how they want to get there couldn't be more different.
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Part 11: Cheese capital
We’re driving through vast grassy plains with very little else around except for the occasional mile-long coal train.
Our next destination is Clovis, the cheese capital of New Mexico. We'll see what's there - but large amounts of jack, Swiss and cheddar seems likely.
But my mind's still on an amazing man we met at the State Fair Rodeo in Albuquerque - Corey, an American bullfighter. He's all taut legs and arms, and hands that vouch for his 18 years in the business.
Bullfighters in the States don't aim to kill, but to distract.
It goes like this. The bull is quietly raging in a tight cage. The cowboy adjusts his jeans, chaps and hat and sticks a foot on the metal bars on either side of his foe.
Then when he's ready – which is something I can't imagine ever being – he drops down on the bare back below him, the gate springs open, and the bull bucks violently until the rider has been dispatched to the floor.
This is when Corey moves in. He jumps between the fallen cowboy and the charging bull, persuading it to go for him, before vaulting out of the way with the help of the horns.
As the MC shouts over the blaring dance music, "He's like a firefighter. When we’re running away, he's going in."
It was impressive stuff.
"That looks very dangerous, Corey," I told him, stating the blindingly obvious.
"It is," he smiled back, "but I know the bulls, and you can suss them out. Some aren't as nasty as they look."
They all looked pretty nasty from where I was standing.
"Are you as good as sussing out politicians?" I asked.
"I'm a Republican, so that's how I'll vote - they have my Christian values," he replied.
And if a cowboy replaced his checked shirt with a "Vote Obama" t-shirt - how would that go down at the rodeo?
"Not real good," chuckled Corie. "But I'd protect him regardless - then I'd have a quiet word."
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Part 10: Troop support
I'm at the New Mexico State Fair in Albuquerque. There's plenty you'd expect like tacos, ferris wheels and cowboy hats.
There's plenty I didn't expect too - like frozen bananas, customised toe rings and a man in Speedos climbing to the top of a 20 metre ladder and jumping into a pool.
But for all the fun of the fair, there was one low-key moment that will stay with me.
Today was Armed Forces Day and as I strolled around just after the gates were opened, a small and slightly disorganised parade made its way through the almost empty fairground.
At the front were two bagpipe players, then three women will silver hair holding flags emblazoned with ‘gold star mums' - that means they've lost children.
And behind them followed a man in his 30s. He walked with a heavy limp and with the help of a stick.
There was a weight about how all of them moved.
Bringing up the rear were twenty or so young troops who marched with purpose and pride if not with fantastic timing.
‘Come on everyone clap your hands,' one man in the last group shouted to no one in particular. ‘There are many men and women who have died for us to be here.'
I found myself clapping.
And no you're not about to hear me taking sides on what's happening in Iraq and Afghanistan. And no I'm not criticising how Americans treat veterans and their families.
It's just the few other people around seemed distracted by the food they were buying, or the call they were taking or the child they were watching. And our collective response, our human response to what has happened to these people's lives just felt dreadfully inadequate.
Across the way, a stall run by the army and the air force was attracting considerable interest from parents and their kids. There were different types of guns and rocket launchers, military vehicles and lots of people in uniform.
I could hardly find anyone who doesn't support the troops, and them being in Iraq for now.