Sinn Fein leader Mary Lou McDonald speaks to the media outside Dublin castle following the referendum on March 9, 2024 in Dublin, Ireland.

Sinn Fein leader Mary Lou McDonald speaks to the media outside Dublin castle following the referendum on March 9, 2024 in Dublin, Ireland. / Getty Images

The island of Ireland is divided into the Northern part, which is part of the UK and the independent Republic of Ireland to the south. But a political party is poised to take power in both places and it has pledged to make the border disappear.