California ? Despite the narrow passage of Proposition 8 in 2008, a slim majority of California registered voters favors allowing same-sex marriage, according to a Field Poll released Tuesday.

The poll’s results — 51 percent in favor, 42 percent opposed, 7 percent undecided — show big differences among age groups, geography and party affiliation.

The results were close to those the Field Poll found in May 2008, six months before voters banned gay marriage by approving Proposition 8, 52 to 48 percent.

The current survey also found that support for same-sex marriage drops below a majority when voters are given another option — civil unions.

Given that choice, less than half — 44 percent — of those polled said they favored marriage; 34 percent said they favored civil unions or domestic partnership; and 19 percent said they favored no legal recognition for gay couples.