The measure, which would allow refusal of wedding-related services to same-sex couples on religious grounds, has problematic wording, says the Senate president.
The ruling was accompanied by a stay, meaning same-sex couples can not yet begin marrying in Virginia.
Lay Catholics from Florida to Germany ask the church to change on same-sex relationships.
The civil rights attorney was honored at the Makers conference this weekend.
LGBT organizations are taking aim at discriminatory marriage laws in two traditionally conservative states.