A majority of California voters oppose a November ballot initiative that would amend the state constitution to limit marriage between a man and a woman, a poll released Friday found.

According to The Field Poll, a majority of voters (51%) would vote against Proposition 8. Only 42 percent said they were in favor of the amendment.

Republicans and Democrats are miles apart on the issue. A majority of Democrats (63%) are against the amendment, while only 27 percent of Republicans are ready to vote No.

Regionally, voters living in California's coastal counties, which include major cities like San Francisco and Los Angeles – nearly 69% of all likely voters – oppose Proposition 8 56% to 37%. While in inland counties, opinions are nearly reversed with 54% supporting the amendment.

In San Francisco, where California's gay marriage movement first gained hold in 2004 during the “winter of love,” voters oppose the amendment by a large majority (67%).

Today's poll results represent a seismic shift in opinion from 2000, when a majority of voters (61%) agreed with a proposition banning gay marriage.

Proposition 8 not only asks voters to alter the state constitution to ban gay marriage, it also would invalidate hundreds of gay marriages that have occurred since June 16th after the California Supreme Court struck down the 2000 ban.

The Field Poll was conducted between July 8 – 14 with a random sample of 672 likely voters.