There is an American expression for something that is utterly obvious but not, for some reason, noticed.
By Justin Webb
BBC News, Washington
Members of the Westboro Baptist Church protest at a memorial to soldiers killed in combat
"Hiding in plain sight", the Americans call it, and the expression came to my mind as I sat in Kansas City airport waiting for an ice storm to pass.
Hiding in plain sight in this state is a revolution in American Christendom, a change of heart that could see American Protestant churches looking increasingly like their European equivalents.
The state of Kansas gets a bad press. It is huge and empty and mostly flat.
In the summer it is uncomfortably hot and prone to tornadoes. In the winter it can be bitterly cold.
Its big cities are not very big and rather grey. It is not in the culinary avant garde.
In the airport cafe they have introduced nutritional advice next to their meals: the fresh strawberries are described as containing no trans-fats - which is a relief, I suppose - but only in Kansas could it be a surprise.
Kansas has also long been home to religious revivals and eccentric preachers, a few of them deeply wacky, to put it mildly.
Creationists, for instance, keep up a constant low-level guerrilla war in this state and, if that is insufficiently odd for you, try going to Topeka to see the Reverend Fred Phelps and his flock at the Westboro Baptist Church.
They entertain themselves by turning up at public events with placards saying: "God hates gays".
Their campaign against homosexuals came to national prominence when they protested (and this really did happen) at the funerals of soldiers who had been killed in Iraq.
The sexual orientation of the individual soldiers was not the issue.
According to the church, all Americans who die there are part of a punishment God is visiting on the United States because of his profound dislike of homosexuality in this country.
The point is that Pastor Phelps and his followers are not much liked by anyone inside or outside Kansas. The "burning at the stake" wing of America's Christian churches - the wing that stresses vengeance over love - is in trouble.
The gentle, Nativity-scene crowd are the ones on the up.
Mr Phelps still grabs horrified attention from foreigners and Americans alike but most religious Kansans (and that means most Kansans) are becoming steadily less aggressive: not less religious but less intolerant.
Opinion polls suggest that younger evangelical Christians are falling out of love with the "big causes" their churches have championed in recent years, in particular with opposing abortion and supporting the Iraq war.
Fire and brimstone
This change is nowhere clearer than in Wichita in southern Kansas.
The Reverend Terry Fox is a man you would have considered until recently to be a typical Wichita preacher: a fire and brimstone merchant.
His sermon, delivered in staccato bursts, with heavy breathing for effect, concentrates on sin, in particular the sin of murdering babies in the womb.
"I am proud to be called the religious right," he blasts. "I am religious and I am right!"
On the day I met him there was "good news": hundreds of thousands of foreigners had just been converted to Christianity including many Muslims.
You would expect the Rev Fox in God-fearing Kansas, to be preaching in a mega-church, an establishment big enough to cope with the crowds.
And until recently he was: the Immanuel Baptist Church near the centre of town was his.
It was easily spotted because of the huge, tubular, white cross, 100ft (30 metres) high and heated from the inside so that it does not freeze and topple over.
But the Rev Fox's cross is all that is left of his ministry at the old place.
He tells me it was time to move on but most locals think he was thrown out for being too dogmatic, too extreme, even in Wichita.
To see Rev Fox in action, I had to go to the Best Western hotel out among the tattier motels and gas stations on the far outskirts of town.
They clear a central atrium for him, they turn down the muzak, they put away the tinselly plastic Christmas trees, and several hundred turn up for a cheerful haranguing.
Rev Fox is not about to be run out of town but he is metaphorically, as well as literally, on the outskirts now.
His hatred of abortion, his contempt for gay rights, his support for the Iraq war have all led him to his current predicament.
At his old church, the new pastor tells me sniffily that he has never had the pleasure of meeting Rev Fox.
The concerns of his ministry are, he said, human rights and the environment.
Golly, this is a big change.
I have come to town to speak to these people about whether they still support the Republican Party but that is a minor issue, it seems to me, compared with the much bigger question of how they still support God.
Hidden in plain sight this Christmas, is the softening of evangelical America.
A million Kansans will be taking their Bibles to church in the coming week but they will not be bashing them.
From Our Own Correspondent was broadcast on Saturday, 22 December, 2007 at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.