AO1: The Senate is constitutionally equal to the House of Representatives, whereas the House of Lords has more limited powers than the House of Commons AO2: This means that the Senate cannot be overruled by the House of Representatives, whereas the House of Commons can use the Parliament Act to pass legislation the House of Lords has rejected AO1: The Senate has exclusive powers to confirm presidential appointments, whereas the House of Lords has no similar power AO2: This can give the Senate significant power within the US political system over a presidential power e.g. when the Republican Senate refused to hold hearings for Obama’s nominee for the Supreme Court AO1: The Senate also has the exclusive power to ratify treaties, unlike the UK where the House of Lords is does not play a role in approving treaties AO2: This gives the Senate influence over foreign as well as domestic affairs, unlike the House of Lords who do not have to be consulted with unless the prime minister chooses to do so AO1: Individual senators have an electoral mandate to call on which strengthens their role within the US political process AO2: The House of Lords, however, are appointed and so have no specific mandate, which makes the UK government less likely to negotiate with the Lords over legislation where there is disagreement, unlike the US where Senate agreement is required for legislation to pass