(CNN) -- Voters in Arizona approved a measure to amend the state constitution so that only a union between one man and one woman would be recognized as a marriage, effectively prohibiting gay couples from legally marrying in the state.

Voters in California, Arizona and Florida will weigh in on constitutional bans on same-sex marriage.

The measure passed by 56 percent in a reversal of direction from 2006, when a similar measure on the ballot failed.

Arizona was one of three states to weigh constitutional amendments banning same-sex unions. Results on similar measures are pending in Florida and California. If California's controversial Proposition 8 passes, it would overrule a state Supreme Court decision that legalized same-sex unions in May.

The projected result was the first of many hot button issues announced in an election where social issues such as same-sex marriage, abortion and affirmative action dominated ballot measures.

Voters in Colorado rejected a measure to define a person to "include any human being from the moment of fertilization," which would have applied to sections of the Colorado Constitution that protect "natural and essential rights of persons."

Nebraska voters approved a measure to prohibit state governments from discriminating against or granting preferential treatment to people based on race, ethnicity, color, sex or national origin. Results on a similar measure in Colorado have not been announced.

Michigan voters chose to make their state the 13th to legalize marijuana for medical purposes by a 64 percent margin. Massachusetts also had a proposed initiative to decriminalize penalties for possession of less than an ounce of marijuana.

Results on abortion-related proposals are still pending in several states, including South Dakota, where voters will decide whether to allow abortions only in cases of rape and incest. California's Proposition 4 requires physicians to provide parental notification to guardians of minors at least 48 hours before performing an abortion.iReport.com: Watch Prop 8 debate in Utah

Don't Miss Ballot measures In Depth: Election Center 2008 Election features Many states also weighed budget-related proposals that could significantly affect how state revenues are generated.

In Massachusetts, voters have rejected a measure to cut the state personal income tax rate in half for 2009 and eliminate the state personal income tax starting in 2010. A similar ballot measure failed in 2002.

A citizen-initiated measure in North Dakota also proposed cutting personal income tax rates by half. Voters in Colorado and Minnesota were asked to consider increasing sales taxes. Oregon's Measure 59 would allow taxpayers to deduct the full amount of their federal income taxes on their state income tax returns.

Voters in eight states considered proposals related to gambling and lotteries. Arkansas had a citizen-initiated measure to establish a state lottery to fund college scholarships.

Voters in multiple states also weighed in on a variety of proposals related to animal rights, gambling, marijuana and renewable energy, to name a few.

Californians could face jail time if voters approve Proposition 2, which outlaws the confinement of pregnant pigs, calves raised for veal, and egg-laying hens "in a manner that does not allow them to turn around freely."

California, which is tied with Oregon with 12 ballot measures, had two initiatives related to renewable energy. One would require some utility providers to purchase or generate a percentage of their electricity from renewable sources, a proposal similar to another in Missouri. California's Proposition 7 and Colorado's Amendment 58 would direct state funding to renewable energy programs.

South Carolina is the only state seeking to amend its constitution to change the age of sexual consent from 14 to 16. Washington is also on its own with a citizen initiative to allow adults with six months or less to live to request lethal medication prescribed by a physician. A physician is not required to comply, but anyone participating "in good faith" with the request would not risk criminal prosecution