"This case reflects a classic tension between democratic values," said Ben Bishin, a political science professor at University of California-Riverside. "People often think that democracy means the will of a majority should be law, but its also about equality and liberty. Questions of minority rights speak to values of equality and liberty, and courts are reluctant to tread on those rights when there's no harm done to society."
A California Field poll of registered voters last month found that 51 percent now support legalizing gay marriage with 42 percent opposed.
Nationwide, public views are more narrowly divided, according to the most recent ABC News/Washington Post poll. Forty-seven percent of Americans polled favor gay marriage while 50 percent are opposed.
Five states -- Massachusetts, Iowa, Connecticut, Vermont and New Hampshire -- and the District of Columbia perform same-sex marriages. Four states recognize marriages performed elsewhere and nine states grant civil unions or partnerships.