While attending University College Dublin, he became auditor of An Cumann Gaelach and of the Literary and Historical Society.

Fine Gael, confident that its prospective candidate Tom O'Higgins would win the 1973 presidential election (he had almost defeated de Valera in 1966), turned down the offer.

While popular with Irish language speakers and with artists, and respected by many republicans, he had a strained relationship with the then government led by Fine Gael, particularly with Minister Conor Cruise O'Brien and Taoiseach Liam Cosgrave.

Following the assassination of the British Ambassador, Christopher Ewart-Biggs, by the Provisional Irish Republican Army (IRA), on 23 July 1976, the government announced its intention to introduce legislation extending the maximum period of detention without charge from two to seven days.

[16] On the same day, an IRA bomb in Mountmellick killed Michael Clerkin, a member of the Garda Síochána, the country's police force.

[17] Ó Dálaigh's actions were seen by government ministers to have contributed to the killing of this Garda given his delay in signing the Emergencies Powers Bill into law having referred it to the Supreme Court.

This proved the last straw for Ó Dálaigh, who believed that Cosgrave had additionally failed to meet his constitutional obligation to regularly brief the President on matters of state.