Designers have noticed a number of flaws in the USA, especially in the the export democracy functions and WMD tracker. They proposed to remedy these through minor upgrades, including the USA1.2 upgrade, dubbed the Kerry upgrade. The Kerry upgrade was unsuccessful; although relatively advanced, its function relied on a series of primitive flip-flops. The Kerry upgrade failed to pass the election criteria. This major setback prompted calls for a complete overhaul, which came to be known as USB.