Mitt Romney's strong record as a former Governor of Massachusetts made him the obvious choice as the Republican presidential candidate. His strength, after all, lies in economic management, the area where President Barack Obama is under most pressure, not least because of a stubbornly high 8.3 per cent unemployment rate.
But Mr Romney also has weaknesses, notably a lack of charisma or an appeal to conservative and evangelical Republicans.
These shortcomings see him trailing the President in opinion polls. Something had to change if his challenge was not to rely in large measure on a sudden deterioration of the American economy. This has been supplied by his selection of free market Congressman Paul Ryan as his vice-presidential running mate.
Mr Ryan's youth and zeal have re-energised the Republican campaign. Even the uninspiring Mr Romney appears rejuvenated. It has become quickly apparent that he has avoided the Republicans' blunder in the last presidential race, when John McCain ran with the inexperienced Sarah Palin.
The 42-year-old Mr Ryan, who chairs the House budget committee and has spent half his life in Washington, is no political tyro. Yet his selection, as with that of Ms Palin, says much about Republican frailties and could yet prove as problematic.