AO1: Checks and balances are more explicit in the US Constitution than in the UK AO2: the US Constitution is codified and entrenched, clearly outlining the checks and balances on the Supreme Court, but in the UK this is not formally entrenched AO1: US Supreme Court cannot be challenged or overruled by other courts, unlike the UK Supreme Court where human rights issues may be taken to the ECHR AO2: the US Supreme Court is the highest court in the land and cannot be overruled by any other court, but UK Supreme Court decisions can be challenged in the European Court of Human Rights (on ECHR cases only) AO1: The US appointment system may affect the power of the US Supreme Court as it may be less able to act independently than the UK Supreme Court AO2: the political nature of the US appointments process allows the potential for the executive to try to influence the conservative/liberal stance of the court - in the US in particular, e.g. Garland's nomination by Obama, Gorsuch's nomination by Trump, whereas the UK Supreme Court justices are appointed by an independent judicial committee rather than the prime minister AO1: The US Supreme Court can declare statute and executive actions unconstitutional, unlike the UK Supreme Court which can only declare actions unlawful or incompatible with the Human Rights Act 2000 AO2: this allows the US Supreme Court more power as when acts/actions declared unconstitutional essentially cancels out those acts, but the UK Supreme Court can only declare statute ultra vires, so relying on the UK Parliament to then amend the law as Parliament is sovereign AO1: US Supreme Court justices have no limit on their terms in office, whereas UK Supreme Court justices have a mandatory retirement age AO2: this means US Supreme Court justices can - and often do - stay in office for life once appointed, and can only be removed by formal impeachment, whereas UK Supreme Court justices must retire at 75. This potentially gives US Supreme Court justices more opportunities to make decisions on far-reaching issues over a longer period of time - and no US Supreme Court justice has been successfully impeached.