Glenn was an outspoken critic of contraceptives, abortion, divorce and other attempts to liberalise Irish society, and much of her commentary was deemed memorable and influential.

She was born in 1921 at Usher's Quay, Dublin, the eldest of ten children of (Arthur) Leo Duffy, a car mechanic, and his wife Mary (née Joyce), a dressmaker.

Already active in a number of women's social clubs in inner-city Dublin, Glenn joined her local Fine Gael branch and rapidly advanced in seniority.

Her husband William brushed aside suggestions that Alice's political career could damage his prospects in the Air Force and remained supportive of her ambitions.

[2] An early example of her conservatism was demonstrated in 1978 when Glenn made a speech in which she suggested 10,000 Irish women should give up their jobs in the public sector in order to decrease men's unemployment.

Glenn, along with Joe Doyle and other colleagues endorsed the Fianna Fáil alternative wording that granted a "right to life to the unborn, with due regard to the equal right of the mother".

[2] In 1986 the Fine Gael-Labour government held a referendum to legalise divorce in Ireland and during the campaign over the summer, Glenn became one of the most outspoken voices on the anti-divorce side.

[2] Although the result was in Glenn's favour, it made her position in Fine Gael effectively untenable, as she was increasingly becoming a pariah within the party.

Besides conflicting with the majority of Fine Gael TDs, Glenn further estranged herself from the party by condemning the government's plans to reform childcare laws as well as touting eurosceptic viewpoints.

[2] In November 1986, just days before a Fine Gael selection convention in Dublin Central, Glenn caused a political and social scandal after she described leaders of all other faiths in Ireland besides Catholicism as "enemies of the people".

[12] Glenn opposed moves to introduce divorce, abortion and contraceptives to Ireland and rejected calls to reform childcare, suggesting such legalisation would interfere with the family.

Glenn cited Arthur Griffith and Daniel O'Connell as political heroes, and welcomed comparisons to Ronald Reagan and Margaret Thatcher.

[12] Unusually for a member of Fine Gael, she also cited the founder of their primary rival Fianna Fáil Éamon de Valera as an inspiration, specifically praising his social conservatism by stating "Thank God for Dev and what he has done.