An effort to enhance penalties associated with violent protests, create new crimes when mobs attack property or police and make it difficult for cities to trim law-enforcement spending had a rocky legislative debut, drawing heated criticism from opponents.

The measure is backed by the state’s three most-powerful Republican leaders but was decried as unnecessary and divisive by Democrats and other critics — many of them young or Black — who unsuccessfully urged the House Criminal Justice and Public Safety Subcommittee to reject the proposal.