The love affair between the United States and Ireland dates back to the early waves of immigration and continues to be reinforced by a mixture of shared values, folklore and nostalgia.
President Bush will get a chilly reception from protesters
St. Patrick's Day - religiously observed as a national holiday in the US - compels tens of thousands of Americans to drink green beer once a year, march to bagpipes or buy plastic shamrocks.
There's the ancestral dimension. Ronald Reagan, whose forefathers were Irish Presbyterians, took Nancy to sip Guinness in a pub near their place of birth.
Even Richard Nixon's White House staff managed to find the grave of a distant Irish relative with which to enliven an otherwise dreary visit.
More recently there were the scenes of near hysteria and jubilation that greeted Bill Clinton on his numerous visits to the Emerald Isle.
Northern Ireland was a hot political topic during his presidency and one in which he became personally involved.
Contrast this with the scenes in County Clare as President Bush jets into Ireland for less than 24 hours on his way to Turkey for what will probably be the last foreign trip of his first term.
The motorways and streets around Dromoland Castle near Limerick, where the president and the first lady will be staying, are almost deserted.
Tourists and locals have been scared away by predictions of protest and a massive security operation that will close down much of this stunningly picturesque county.
Some 2000 troops, many of them in armoured vehicles have surrounded Shannon airport, and 4000 officers from the Irish Garda wearing green fluorescent jackets line the streets, scouring the ground for bombs and the horizons for protesters.
The forest that already conceals Dromoland Castle from public view has been surrounded by a freshly built, camouflage green fence, presumably to keep the most determined of protesters at bay - those who have managed to break through the 10 mile security cordon.
The only American flag I spotted was in a camp of anti-American protesters and it was adorned with a skull and cross bones.
The president is making his second visit to Europe in a month
For the first time, an American president comes to Ireland greeted by silence and an almost complete absence of cheering crowds.
The majority of Irish did not approve of the war in Iraq.
And even today the Irish justice minister joined a swelling chorus of discontent from the UN Human Rights Commission to the British attorney-general berating the administration for the detention of prisoners at Guantanamo Bay and the ensuing military tribunals.
Anti-Bush demonstrations have been planned in a number of Irish cities and the usual gush about Ireland's most powerful friend has been conspicuous by its absence.
How much of this will be noticed at home in the United States is an open question.
Like every other president, George Bush wants to court the Irish vote at home in an election year.
A cursory visit may be enough to persuade some Irish Americans that he cares about them more than his Catholic Democratic rival from Irish bastion of Boston.
The other objective of this first leg of his visit is to rebuild bridges with Europe.
Much of this has already been done through diplomatic channels, at the UN in New York, on the beaches of Normandy and at the G8 Summit in Savannah.
After a difficult year of disagreements over Iraq, the EU and the US realise that they need each other in Iraq and elsewhere.
But even if relations have improved, one gets the impression that hearts from both sides aren't in it and that much of Europe is waiting to see exactly what will happen on 2 November in the American polls.
In less troubled times, Bill Clinton used the annual EU-US summit as a catwalk from which to dazzle his audience and flaunt his international street cred.
By way of thanks, he became the first American president to receive the Charlemagne prize for his contribution to European Unity.
Previous winners included Winston Churchill and Vaclav Havel.
President Bush is not on the shortlist for the prize, a fact which is unlikely to vex him and his supporters.
The diplomatic bridges may have been rebuilt between Europe and America but the chill waters of mutual misunderstanding, suspicion and distrust continue to flow underneath.