Paul Pelosi, the husband of US House of Representatives Speaker Nancy Pelosi, is recovering from surgery after being attacked at home by a hammer-wielding intruder.
Mr Pelosi, 82, was left with a fractured skull and serious injuries to his right arm and hands.
The suspect is said to have demanded to see Mrs Pelosi after breaking in to the San Francisco home.
A 42-year-old man has been arrested on charges including attempted homicide.
No motive is known.