The candidate said her donors' contributions "will never be used to enrich these chilling right-wing efforts."
The Republican-led state legislature has indicated it will challenge the ruling at the Supreme Court.
"The court has made it abundantly clear that partisan gerrymandering will not be tolerated," said attorney David King.
It's a big deal, but it may not be the answer to partisanship.
By 5-4, the court ruled that the initiative did not violate the U.S. Constitution's requirement that state legislatures set congressional district boundaries.