MARYLAND THIS year joined 16 states in extending protection to transgender people in housing, lending, employment, public accommodations and other areas. Now a conservative group, including some of the Republicans who opposed the legislation, is trying to force the issue onto the state ballot this fall, in the hopes that voters will reject it. If it manages to get the proposal on the ballot, it’s not likely to prevail if recent history is any guide. Nor should it.

Incredibly, the conservatives’ main line of attack is that the law will turn women’s restrooms into fertile ground for peeping toms disguised in dresses and wigs, even for similarly attired rapists. This is middle school trash talk disguised as policy analysis. There is no evidence that this is a statistically detectable problem in other states that have banned discrimination against transgender people, nor in Maryland localities, such as Montgomery County, that have had similar statutes on the books for years.

For one thing, the law’s rigorous definition of a transgender person — someone whose core identity is expressed by consistent and uniform expression — does not extend to men who might get their kicks wearing dresses to spy on women. For another, transgender people generally already use restrooms consistent with their gender identity, according to their advocates.

More broadly, opponents of the legislation tend to miss its central point, which is to ban the blatant discrimination that transgender people report is pervasive. In a 2011 survey conducted by the National Gay and Lesbian Task Force and the National Center for Transgender Equality, 71 percent of transgender people in Maryland said they had experienced harassment or mistreatment at work and 18 percent said they had lost a job or been denied a promotion as a result of their gender identification. Seventeen percent reported having been denied housing. Shocking numbers of students in public schools report harassment (81 percent) and assaults (38 percent).

In seeking to rally support for overturning the law at referendum, Del. Neil C. Parrott (R-Washington) has focused on the supposed risks it may pose in public restrooms. But Mr. Parrott opposed the anti-discrimination legislation several years ago when it did not even include public accommodations.

Republican legislators opposed the legislation en masse, much as they opposed extending in-state tuition rates to undocumented immigrants two years ago. In the case of the tuition issue, Maryland voters demonstrated that they were more tolerant than opponents predicted; when Republicans forced that legislation onto the state ballot in 2012, voters upheld it at referendum by a wide margin.

Mr. Parrott and his allies need to gather more than 55,000 petition signatures to compel a vote on the anti-discrimination bill. If they accomplish that, Maryland voters will again have a chance to demonstrate their preference for tolerance.