South Dakotans rejected on Tuesday a toughest-in-the-nation law that would have banned virtually all abortions, even in cases of rape and incest -- defeating one of the most high-profile state measures facing voters.
The outcome was a blow to US conservatives, who also had cause for worry in Arizona. An amendment to ban gay marriage was trailing there with returns nearly complete; it would be the first defeat for such a measure after prevailing in more than two dozen states in recent years.
In Michigan, voters decided that race and gender should not be factors in deciding who gets into public universities or who gets hired for government work.
The state joins California and Washington in banning some types of affirmative action programs -- a move that comes just weeks before the US Supreme Court is to hear arguments in two cases that could mean big changes in federal affirmative action law.
Nationwide, a total of 205 measures were on the ballots in 37 states on an array of the US' most divisive social issues such as boosting minimum wages and tobacco taxes and legalizing marijuana.
The referendums, know as ballot measures, are proposed state laws that must be approved or rejected directly by voters within states. They are often held in conjunction with general elections for practical reasons.
In Missouri, returns were too close to call on a proposed amendment allowing stem cell research. It had been a factor in the crucial Senate race there and it got national attention after actor Michael J. Fox, who suffers from Parkinson's disease, appeared in a controversial campaign advertisement supporting it.
No measure had riveted political activists across the country like the South Dakota abortion measure. Passed overwhelmingly by the legislature earlier this year, it would have allowed abortions only to save a pregnant woman's life.
Had the ban been upheld, abortion-rights supporters would likely have launched a legal challenge that could have led to a US Supreme Court reversal of the 1973 Roe v Wade decision legalizing abortion.
Jan Nicolay, a former state legislator who led opposition to the ban, said voters viewed the measure as too intrusive.
"We believe South Dakotans can make these decisions themselves," she said.
"They don't have to have somebody telling them what that decision needs to be," she added.
Eight states had ban-gay-marriage amendments on their ballots; Idaho, South Carolina, Tennessee and Virginia joined Wisconsin in approving them, while results were pending in Arizona, Colorado and South Dakota. Similar amendments have passed previously in all 20 states to consider them.
Several states already had laws against same-sex marriages, but supporters said constitutional amendments would prevent activist judges from possibly opening the door to gay unions.
Conservatives hoped the same-sex marriage bans might increase turnout for Republicans. Democrats looked for a boost from low-income voters turning out on behalf of measures to raise the state minimum wage in six states. The wage hike passed in Arizona, Missouri, Montana, Ohio and Nevada; results were pending in Colorado.
Arizona voters were deciding on the most ballot measures: 19. Voters passed four measures targeting illegal immigrants, including one expanding the list of government benefits denied to them. Another measure makes English the state's official language. The US has no national law mandating English, and proponents said the Arizona measure would urge immigrants to assimilate.