To borrow from Shakespeare’s Julius Caesar, upon what meat doth this our vice-president, Dick Cheney, feed that he has grown so great? Mr Cheney’s imperial vice-presidency has trampled the conservative constitutional philosophy of the Founding Fathers. He has used the law to evade checks and balances. For example, he declared himself part of the legislative branch – as president of the US Senate – to exempt his office from President George W. Bush’s order governing classified information. But days later he draped himself in the mantle of the presidency to defend the confidentiality of vice-presidential communications and claim immunity from suit for any constitutional violations.

The constitution entrusts the vice-president with a single puny chore: to preside over the Senate, without a vote except to break ties. Occupants of the vice-presidency have bewailed its insignificance. Their typical tasks have been handing out blankets after earthquakes and attending state funerals. Presidents have been characteristically jealous of their constitutional turf.