Look at a map of the Democratic presidential primary so far and you will see Bernie Sanders’s colour dominates northern states and Hillary Clinton’s the south, save for a few pockets up north.
Some of those pockets are in Massachusetts, a state that is interesting from an Irish perspective.
While the existence of a homogenised Irish voting bloc in US politics is very much disputed – in fact, it is split among Democrats and Republicans – some say Irish-American voters helped Clinton edge it in Massachusetts.
Brian O'Dwyer, a New York-based lawyer and major Clinton supporter, said that her narrow win in Massachusetts – 50.1 per cent to 48.7 per cent – was "the primary that broke the back of Bernie Sanders's campaign", showing that the Vermont senator could be beaten in his New England stronghold.
Massachusetts is the only northeastern state Clinton has won so far, and it wasn't as big a win as her 15-point state victory over Barack Obama in 2008.
O'Dwyer claimed the March 1st win for Irish-American voters, payback for the support shown by the Clintons to Ireland.
“It showed she can count on the Irish,” he said. “If she had won all the areas in the south and not Massachusetts, maybe she couldn’t win.”
Drilling down into the voting, two areas swung it for Clinton: Boston and Springfield, both with large Irish-American populations.
Clinton won Boston by 19,898 votes, or a 16-point margin, more than her entire margin of victory in the state (17,068 votes). She won Springfield by an even wider margin – 23 points, with 11,550 votes to Sanders’s 7,202.
"There is an unyielding loyalty to the Clintons for what they did in Northern Ireland and how they pay attention to Ireland," said Democratic congressman Richard Neal, whose Massachusetts district includes Springfield and borders Sanders's home state of Vermont.
Clinton held rallies in Boston and Springfield the day before the Super Tuesday ballot. She was helped in Boston by having the support of every major Democratic figure in the state, including the city's popular mayor, Marty Walsh, the son of Co Galway natives.
At the Springfield rally, Clinton mentioned the role she and her husband – and Neal, standing next to her – played in the Peace Process.
“Most particularly, we worked to end the Troubles in Ireland,” Clinton said. “To give the people of Northern Ireland a chance for peace and security.”