The Arizona House plans a second vote on a bill preventing the Arizona Citizens Clean Elections Commission from investigating possible campaign contribution violations by candidates who don't participate in the program.
The Senate-approved bill would allow only the Secretary of State and state Attorney General to investigate.
Senate Bill 1344 failed on a 29-25 vote on Monday but a reconsideration vote is planned Tuesday because two Republicans did not vote. Thirty-one votes are required for House passage.
Republican sponsors say the law creating the commission doesn't give it authority to investigate candidates who don't take public campaign funding.
The commission says the act grants them that authority and announced last year it planned to begin doing so.
The act provided campaign funding to candidates if they forgo private donations.