The day after the 2006 congressional election, George W Bush admitted Republicans had received a “thumping”. President Barack Obama called his 2010 humiliation at the hands of the Tea Party a “shellacking”. Another noun may be called for on Tuesday when Republicans are likely to regain control of the US Senate. People assume Mr Obama will then face two long years of lame duckery before he is finally put out of his misery. Yet with fresh blood, and a new approach, the final quarter of a presidency can also become its redemption. Mr Obama should take a leaf from George W Bush’s book.

The president has spent much of the past six years defining his administration against that of his predecessor. Mr Bush launched a misguided war of choice in Iraq, mishandled the one of necessity in Afghanistan, passed generous tax cuts for the wealthy at a time of falling blue-collar incomes and questioned the notion of man-made global warming. But when Mr Bush was bloodied by US voters in 2006, it appeared to knock sense into him. He embarked on a course correction that went some way towards retrieving his presidency.

At its heart was a change of personnel. The day after Democrats regained control of Capitol Hill, Mr Bush fired Donald Rumsfeld, his pugnacious Pentagon chief, and brought in Robert Gates. This proved a big improvement. Mr Gates handled a successful US troop surge in Iraq and restored relations with “old Europe”. A few months before the midterm disaster, Mr Bush had replaced John Snow, the beleaguered Treasury secretary, with Hank Paulson, who became the president’s most pivotal cabinet member. Mr Paulson helped to launch the Group of 20 leading industrial nations, declared global warming to be real and was central to the disaster management after Lehman Brothers collapsed in September 2008.