The February 2020 general election in the Republic of Ireland sent shockwaves through the country's political system. Sinn Fin, ahead of all other parties in terms of first preference votes, secured its place as a potential coalition partner, a role it has been playing in Northern Ireland since the start of the century. This result not only disrupted the two-party system, it also questioned a narrative that had cast Sinn Fin as an outlier in the political mainstream. However, the prospect of this all-Ireland, radical left and former Provisional IRA associate being in government raises many questions: what does the success of this all-Ireland party say about the prospect of reunification? Can a party over which the shadow of paramilitaries still lingers be fully trusted? And are the radical changes that the party advocates in areas such as housing, public health and taxation a compelling alternative? These are the questions that this book sets out to address.