A costly campaign by abortion-rights advocates for state supreme court seats yielded mixed results in Tuesday's election, with Republicans expanding their majority on Ohio's court while candidates backed by progressive groups won in Montana and Michigan.

Michigan Democrats and their allies are defending their majority on the state's Supreme Court after a campaign marked by exorbitant spending.

Two seats are up for election on Michigan’s Supreme Court, where Democratic-backed justices hold a 4-3 majority. Court races are technically nonpartisan, but candidates are nominated at party conventions.

Ohio voters will make decisions on three supreme court races that will determine which political party controls the bench.