The fiancée and sisters of Robert McCartney, who was murdered in Belfast, shook hands with George W Bush and secured his support for their search for justice. In recent years, the gatherings in the US on St Patrick's Day have become a key part of the Northern Ireland peace process.
Millions of people across the world celebrated St Patrick's Day
It is a good job that whoever decides these things in the church did not make St Patrick the patron saint of subtlety.
Somehow, over the years he seems to have grown to suit the festival of green beer and portly middle-aged men in leprechaun suits that now bear his name.
I awoke in my Washington hotel room to the sound of a breakfast show host wishing me 100,000 welcomes in excruciating Irish.
I went to bed to a weather forecast in which graphic shamrocks the size of Wyoming cascaded down a cartoon map of the continental United States.
On my way to work every day I passed an African American saxophonist busking with a collecting cap perched on a sign that read "Homeless, but not sitting on my arse shaking a can".
He marked St Patrick's Day by playing a bluesy version of Danny Boy, as though it was not bluesy enough in its original form.
I threw in a handful of change and he paused.
"You Irish?" he asked.
I live there, I replied.
"Today everybody's Irish," he said, "putting his instrument back to his lips."
That side of St Patrick's day, the side that has publicans selling unappetising-looking green lager, will never go away.
There has always been an American dimension to Irish political life
But in recent years, in Washington in particular, the feast has acquired a new and rather weightier meaning.
Much of the political establishment from either side of the border decamps here to lobby, and to brief, and to pick up signals from the wealthy and powerful figures at the top of the Irish American establishment.
There has always been an American dimension to Irish political life.
Republicans raised money and ran guns from here. Other nationalists always saw the United States as a kind of court of appeal against British influence.
Ulster Protestants will tell you that 17 of the 43 US presidents had Scots-Irish roots, and that Davy Crockett's family were Ulstermen too.
Former US President Bill Clinton encouraged the peace process
In recent years the importance of that dimension grew, and not just because Bill Clinton fancied Ireland as one of those issues where a successful resolution might secure a statesman a place in history.
Irish America supports the peace process and follows it in detail.
It hands out huge amounts of money along the way to causes like integrated education, the bringing together of Protestant and Catholic school children, which is a ray of hope for the future.
Over the last few days I have found myself discussing the nuts and bolts of police reform with a couple from Cleveland, and the prospects for change in the local government structure with the Mayor of Peoria, Arizona.
And so of course, Irish America has embraced the sisters and the fiancée of the murdered Belfast family man Robert McCartney, the victim of a bestial attack by IRA men who are now intimidating potential witnesses to ensure that they will not be brought before a court.
The McCartneys travelled to America to campaign for justice
The McCartneys saw President Bush, and met Ted Kennedy and Hillary Clinton on Capitol Hill.
They dined with the leaders of the Irish American lobby and were applauded for the dignity and the courage with which they have stood up to the IRA, and this in a community where once the IRA had found plenty of understanding too.
They make a striking image.
Six women filmed outside the White House and the Senate explaining how their grief and anger give them the courage to face down a terrorist organisation, which dominates the tiny Catholic enclave where they live in Belfast.
People were struck by the way in which the sisters, who were only thrust into the limelight by the tragedy of their loss, had somehow found it in themselves to act with great poise under a degree of scrutiny that would have rattled many seasoned politicians.
They appear to have the strength to cope with bereavement and to search for justice too
"God makes the back to bear the load," one woman said to me.
A curious Irish expression I had heard as a child from my mother. It means roughly that providence never afflicts you with problems that you cannot manage.
I am not sure about the underlying theology, but I knew what she meant about the McCartneys.
They appear to have the strength to cope with bereavement and to search for justice too.
The IRA still has its supporters in America, of course, and it always will.
Northern Ireland politicians have attended festivities since 1993
But the circumstances of Robert McCartney's life and death, and the loyalty of his fiancée and his sisters have prompted a good deal of thought among the Irish Americans that I have been speaking to.
It is as though the case is a fixed point for them around which a better understanding of life in Northern Ireland is crystallising.
The extent of paramilitary power to kill at will and to intimidate witnesses, the scale of criminality, the fear and the uncertainty.
"It is," said one man, "a depressing thought that even seven years on from the Good Friday Agreement, so much remains to be done, but these girls show you that there's still hope."
It seemed appropriate that he wanted to find a note of optimism to mark St Patrick's feast day.
Like any Irish American he wanted to help, but I could not help feeling that somehow he had realised, like many other people in these last few weeks, that Northern Ireland can still seem a bleak place, its problems intractable.
From Our Own Correspondent was broadcast on Saturday, 19 March, 2005, at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.