In 2014, lawmakers put a similar advisory referendum on the ballot calling for state millionaires to pay 3% on income exceeding $1 million, with proceeds specifically earmarked for schools. Nearly two-thirds of voters on that question — 64% — backed the idea.

Illinois voters approved three nonbinding ballot questions, including one asking whether the highest earners should be taxed to fund property tax relief.

The measure calls for the creation of a 3% tax on individual income over $1 million to use to reduce the property tax burden.

The ballot asked if voters would support a 3 percent surcharge on incomes over $1 million to support property-tax relief.