BATON ROUGE, La. (AP) — A super PAC supporting Republican U.S. Sen. David Vitter is asking a federal judge to throw out the state's donor limits to political action committees.

The Fund for Louisiana's Future filed a lawsuit in New Orleans federal court Tuesday, challenging the limits as an unconstitutional limit on political speech.

Louisiana currently caps contributions to PACs at $100,000 for each election cycle. Super PACs can raise and spend unlimited funds to help candidates at the federal level.

The state ethics board refused to jettison the cap, saying it didn't have the jurisdiction to declare a state law unenforceable or unconstitutional.

Created last year, the Fund for Louisiana's Future is raising money to independently advocate for Vitter, who is running for governor in 2015. It has raised $1.5 million for the effort.