LONDON — On the day when Rupert Murdoch retreated from the biggest media takeover bid in Britain’s history, the wider significance that many here see for the way that power in the country is wielded found its most poignant expression in the sight of an ordinary family standing silently, subdued but assuaged at last, at the door of 10 Downing Street.

It had taken less than 10 days for the anger that swept Britain over the story of Milly Dowler’s cellphone to build into the political earthquake that forced Mr. Murdoch, the 80-year-old tycoon, to abandon the latest, and what could be the last, of his great business coups — an attempt to acquire the rest of British Sky Broadcasting for the News Corporation, the corporate giant that makes Mr. Murdoch one of the world’s most powerful news media figures.

The Dowlers had been shielded, until Wednesday, by their lawyer, Mark Lewis. He has fielded a frenzy of media questions since the news broke last week that, according to the police, a Murdoch-owned tabloid, The News of the World, had hacked into the voice-mail messages of the 13-year-old Milly after she was abducted in 2002 and while her family waited for some sign that she was still alive.

That sign came, the family thought, when the police told them that some of the messages they had left on the cellphone that Milly was carrying had been deleted. In reality, the police said, the messages were erased at the newspaper’s behest, to make room for more messages that could be hacked to embellish articles on her disappearance. Ms. Dowler was later found murdered.