Gay rights opponents have failed in an attempt to repeal California law on gay history teaching in schools.
They did not manage to collect the 505,000 signatures needed to suspend the law and put the issue on the ballot.
The Pacific Justice Institute, which has been campaigning against the law, said it and other opponents collected about two-thirds of the necessary petition signatures.
Brad Dacus, president of the group, suggested opponents would target lawmakers in next year’s elections.
He said they would would ” pay a price” for the “disrespect and intolerance of parents’ viewpoints”.
However, the Traditional Values Coalition told Associated Press that they had decided not to file the challenge regardless of the signatures gathered.
The Fair Education Act, passed this year, ensures that all children learn about figures such as San Francisco gay rights campaigner Harvey Milk.
It also bans “discriminatory” teaching material. It comes into force in January.
California law already requires schools to highlight the contributions of women, African-Americans, Mexican Americans and entrepreneurs, among others.