The Colorado Court of Appeals issued the ruling Thursday, affirming a lower court's decision.
At issue was a change from Gessler's office to raise the financial disclosure threshold for political groups from $200 to $5,000. The court says that violates what voters put in the Colorado Constitution in 2002.
Gessler argues that his aim has been to bring state campaign-finance laws in line with a recent federal appeals court ruling and to ease a complex process.
Opponents argued that raising the threshold would make it easier for political groups to avoid disclosing financial interests for ballot initiatives.
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