BOISE, Idaho — Legislation with the potential to fine Idaho librarians $1,000 and send them to jail for a year for checking out material to a minor that could harm them cleared the House on Monday.

The House voted 51-14 to approve the measure that backers said will protect children. But opponents said it is so undefined and subjective as to be unconstitutional.

Democratic House Minority Leader Ilana Rubel asked Republican Rep. Gayann DeMordaunt, the bill’s sponsor, if a classic young adult novel by Judy Blume that included masturbation could land a librarian in jail. DeMordaunt refused to answer.