They were short, sometimes just one word, such as "Why?" And she often challenged lawyers arguing cases big or small to tell her the real-world effect that a Supreme Court ruling on the matter would have.
O'Connor, who announced her retirement Friday at age 75, was a pragmatist among ideologues, a centrist whose vote could often be a tiebreaker on the court's most contentious issues. Off the bench, she was both generous and demanding, and fully aware of the intimidating effect she had on other people.
The toughness and independence of her upbringing on an Arizona a ranch showed in O'Connor. She could be short-tempered and blunt, and she did not suffer pesky reporters lightly. She was accustomed to asking the questions, not answering them.
Her gaze, with cool blue eyes, is direct and uncompromising. When asked a question she disliked, such as when she would retire, she sometimes said nothing at all.
The first woman to serve on the court, O'Connor was a crucial vote in holding the middle ground on landmark rulings from abortion to abuses in money and politics.
O'Connor held the center while the court became more conservative in the 24 years since President Reagan appointed her. Still, she often sided with the more conservative justices, as in the ruling that handed Bush victory in the 2000 election.