Once places reserved for those in local authority care and siblings of existing pupils have been allocated - the majority of schools allocate places on the basis of proximity to the school.
On social issues the choice is starkest: though the president has little authority over abortion, contraception, gun law or gay rights (these issues are reserved to the states), the number of ageing justices on the Supreme Court means that a Republican president, especially if re-elected in 2016, could turn the court conservative for a generation.