<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> A presidential system is a democratic and republican system of government where a head of government leads an executive branch that is separate from the legislative branch . This head of government is in most cases also the head of state, which is called president . </P> <P> In presidential countries, the executive is elected and is not responsible to the legislature, which cannot in normal circumstances dismiss it . Such dismissal is possible, however, in uncommon cases, often through impeachment . </P>

What type of government system does the usa have