Are there really more than 400 'anti-trans' bills?

As the battle over transgender-related legislation heats up in statehouses across the country, some Democrats and activists have warned that transgender people are under attack from an avalanche of dangerous proposals.

The huge number of bills is often cited in conversations about the urgency of advancing transgender rights.

Some of the bills lumped into the statistics take a harsher approach than others. For example, several states have moved to criminalize any effort by healthcare professionals to provide gender transition surgery to a minor under any circumstances.

The latest flashpoint in the battle over transgender rights came...