Next Friday, several hundred Irish-Americans, mainly from the New York, Boston and Washington areas, will gather at the White House to welcome President Clinton back from his Irish trip and honour him for his role in the peace process.
These will be activists whose loyalty to Clinton's party, the Democratic party, is assured. But across the US there are millions of Irish-Americans who have in recent times switched to voting for the Republican Party. President Clinton and his aides would love to think that this week's swing through Belfast, Omagh, Dublin, Limerick and Ballybunion will help bring these "defectors" back to their traditional Democratic roots, although this was not the primary purpose of the trip.
Certainly, it should do the President's battered image some good. The TV pictures of him moving through the crowds in Omagh and being applauded on Armagh's Mall by young and old will play well back in the American heartland.
But this kind of coverage is, of course, ephemeral and quickly erased - sometimes on the same day by events such as the terrible Swissair crash off Newfoundland which killed over 100 Americans. And Northern Ireland is not going to be an issue in the midterm elections next November where the Democrats' hopes of recapturing a majority in the House of Representatives are diminishing.
The Monica Lewinsky affair and now falling stocks on Wall Street will overshadow these elections. No Democrat wants to campaign against a background of a tainted President in the White House and a Dow Jones on the slide.
Yet even opponents of President Clinton will give him credit for his work for peace in Northern Ireland. He has listed it as one of his foreign policy successes in nearly every speech over the past year. The bomb in Omagh with its dreadful toll of death and injuries will have blunted this success, however. How can the worst single atrocity happen at a time when the President is vaunting his success in bringing peace to Northern Ireland? For Americans who are not reading daily analyses of the twists and turns of the peace process, the images this week from Northern Ireland should give assurances that the Omagh bombing was not also a bloody end to the peace process. But many will also want to reserve judgement and will not be impressed if the news over the coming months is more bombs - as Mr Clinton predicted himself - or tiresome squabbling by politicians.
Even if President Clinton is given full credit for his undoubted engagement in the peace process, there is no guarantee that this will attract additional political support among the estimated 40 million Americans of Irish ancestry. There are many who approve fully of what he is doing for Ireland while still voting Republican.
It may seem strange that there are probably as many Republican Irish-Americans in an activist role on Northern Ireland in Congress's House of Representatives as Democrats. The Republican Speaker of the House, Mr Newt Gingrich, has just returned from a week-long visit to both parts of Ireland, where he led a bipartisan delegation.
In the Senate, the heavyweights on Northern Ireland are still Democrats, such as Edward Kennedy, Chris Dodd and Patrick Leahy. In the House, one of the most active on Northern Ireland is Congressman Pete King who holds a House seat for the Republicans in Long Island. He and others such as Ben Gilman and Jim Walsh who hold influential committee posts are elected every two years as Republicans with thousands of Irish-American votes.
They have an advantage as Republicans because that party since 1994 controls both the Senate and the House, a rare phenomenon in US politics. But this has meant that Irish-American Republicans have used their power in Congress to support the peace process and if this has meant supporting President Clinton for what he is doing, so be it.
Irish-Americans who vote Republican do so for economic and ideological reasons. The Democratic party is still trying to win back the large numbers who switched to Ronald Reagan in the 1980s because he promised lower taxes and seemed more likely to protect their increasing living standards as they moved upwards from the blue-collar jobs of their parents.
For Catholics, the anti-abortion stance of the Republicans is more attractive than the pro-choice policy which Democrats, especially women, see as a touchstone of the party's liberalism.
Northern Ireland's troubles and successes are dwarfed in the American political scene by comparison with the big issues, such as the economy, taxes, education, crime and abortion. Irish-Americans from both parties will give the President credit for his role in Northern Ireland but this will not necessarily influence how they will vote.
Those who continue voting Republican will say that on Northern Ireland both parties support the peace process and you don't have to switch to the Democrats to show you approve of what the President did this week.
But the Irish-Americans who will salute him on the South Lawn of the White House next Friday know that such a visit and such an event was unimaginable under any previous President. They have an access to the White House which may never come again, and they know it.
They also know the President has his failings. They will be privately shocked at his admission that the affair with Ms Lewinsky was true and not a "vast right-wing conspiracy" but they still know that for Ireland his heart is in the right place.