LANSING, Mich. (AP) — Republican gubernatorial candidate Bill Schuette is criticizing Democrat Gretchen Whitmer for backing a 2013 overhaul of Michigan’s largest health insurer that also stripped the attorney general’s power to regulate premiums requested by Blue Cross Blue Shield.

Schuette said Wednesday Whitmer’s vote led to “massively higher” costs for supplemental insurance that covers Medicare recipients’ coinsurance and deductibles.

The 2013 law enabled Blue Cross to become a nonprofit mutual insurer while ending its exemptions from paying state and local taxes. The insurer committed to contributing $1.6 billion to a health endowment.

Whitmer’s campaign says the law was necessary to ensure people had health care and won overwhelmingly bipartisan support, including from Schuette’s running mate.

Whitmer launched TV ads Wednesday featuring praise from Detroit Mayor Mike Duggan and Wayne County Prosecutor Kym Worthy.