When American voters go to the polls on 4 November, they will not just be choosing a president, BBC reported.
In many states, they will also be faced with a number of referendum questions, known as propositions or ballot initiatives. If passed, they will change state laws.
And many of them deal with issues on the frontline of American politics, from gay marriage to abortion.
The most high-profile ballot initiative in this election cycle is probably California's Proposition Eight, or Prop Eight, as it is known for short.
If passed, it would amend California's constitution to say: "Only marriage between a man and a woman is valid or recognised in California."
The proposition has been put forward by opponents of gay marriage in the state, in response to the California Supreme Court's decision in May 2008 to overturn a law introduced by a 2000 proposition, which had defined marriage in state law as being between a man and a woman only.
Opponents of same-sex marriage want to place their definition of marriage in the state's constitution, thus preventing the state's Supreme Court from overturning it.
Although Californian voters opted in 2000 to outlaw same-sex marriage, the battle this year is very tight.
Polls suggest that voters now oppose attempts to amend the constitution, albeit by a very small margin.
Opponents of the measure say they may be helped by the popularity of Barack Obama at the top of the ballot - but also harmed.
Mr Obama will bring out liberal voters who support same-sex marriage, but he will also increase turnout among African-Americans, many of whom oppose it.
Voters in two other states - Florida and Arizona - will also consider constitutional amendments to ban same-sex marriage.