FACTBOX: Ballot initiatives and the 2008 election

(Reuters) - "Ballot initiatives" in which voters are asked to decide on proposed amendments to state constitutions or legislation are a staple of U.S. elections that have played a big role in recent presidential races.

The proposals are placed on the ballots when people vote in presidential or congressional elections. Proposed amendments to ban gay marriage played a role in President George W. Bush's 2004 re-election victory by energizing the Republican Party's conservative Christian base.

Following are some of the initiatives that already have qualified to be on the ballot or are in the works that could have an impact on the November White House election.

GAY MARRIAGE/GAY RIGHTS:

Florida - Amendment 2 asking Floridians to vote yes or no to a proposal to define marriage as a union between a man and a woman will be on the ballot. Florida is seen as a crucial swing state in the presidential election.

CALIFORNIA - Signatures are being gathered in California, another important state, to have a similar proposals on its ballot. The petition must have 700,000 signatures gathered by April 28 for the proposal to be placed on the ballot.

ARKANSAS - Signatures are being sought to propose a measure to change state law to ban unmarried couples from adopting or serving as foster parents. Gay rights activists say same-sex couples are the target of this initiative.

AFFIRMATIVE ACTION/CIVIL RIGHTS

COLORADO - A proposed constitutional amendment will be on the November ballot in Colorado that says: "The state shall not discriminate against or grant preferential treatment to any group or individual on the basis of race, sex, color, ethnicity or national origin in the operation of public employment, public contracting or public education."

Attempts are under way to get similar proposals on the ballot in Arizona, Nebraska, Oklahoma and Missouri. Initiatives are spearheaded by the American Civil Rights Institute.

Critics say they are aimed to end affirmative action and get conservative Republicans out to vote.

ABORTION:

CALIFORNIA - Signatures are being gathered for a ballot proposal requiring parental notification before a minor can get an abortion.

SOUTH DAKOTA

Signatures are being gathered for a proposal to ban abortion except in cases of rape, incest or if the pregnancy threatens the mother's health or life. The signatures must be submitted by April and 16,776 must be collected.

(Sources: California Secretary of State, Florida Department of State, South Dakota Secretary of State, Family Research Council, American Civil Rights Institute, Ballot Watch) (Reporting by Ed Stoddard; Editing by Doina Chiacu)