Seán MacBride's new party appealed to disillusioned young urban voters and republicans. Many had become alienated from Éamon de Valera's Fianna Fáil, the main republican party in Ireland, which in the view of more militant republicans had betrayed their principles during the Second World War by executing Irish Republican Army (IRA) prisoners. Clann na Poblachta also drew support from people who were tired of the old Civil War politics and wanted more concern for social issues. In post-war Europe many people blamed the social evils of unemployment, poor housing, poverty and disease for the rise of fascism and communism. This new mood influenced people in Ireland also. Some people saw Clann na Poblachta as a replacement for Fianna Fáil. Others saw in it a replacement for the marginalised Sinn Féin, others still a break from the traditional pro- and anti-treaty Civil War division. The new party grew rapidly during 1947.