It has become a hallmark of the St. Patrick's Day holiday: the entire political elite of Ireland descending on the White House.

Not this year. Northern Ireland's unity government is in turmoil, and its Protestant and Catholic leaders have decided to stay put in Belfast to try to resolve their troubles. At risk is an 8-year-old governing coalition of British Protestants and Irish Catholics, a cornerstone of peacemaking for the British territory.

First Minister Peter Robinson and Deputy First Minister Martin McGuinness spent Monday leading their parties in Belfast negotiations. Robinson's Democratic Unionists represent most Protestants, McGuinness' Sinn Fein most Catholics.

The Republic of Ireland's prime minister, Enda Kenny, and the Sinn Fein party leader, Gerry Adams, are among Tuesday's White House guests. Adams has no role in Belfast power-sharing.