In response to Mike Huckabee's theoretical claim, from a legal standpoint, it is important to realize that laws protecting transgender people using gendered facilities consistent with their gender identity do not overwrite other laws: regardless of gender identity, sexual harassment remains sexual harassment, rape remains rape, and so on.
The provisions surrounding gendered facilities in anti-discrimination laws aim to prevent well-behaved transgender people being arrested or ticketed for simply using these facilities, e.g., Tyjanae Moore, Paula Witherspoon, Brenda Wernikoff, businesses preventing these transgender people these facilities (thereby humiliating them), e.g., Ally Robledo, Alex Wilson, River Song, and transgender people losing their jobs over bathrooms, e.g., Etsitty.
Prof. Tobais Wolff in Civil Rights Reform and the Body describes the implausibility of exploiting anti-discrimination laws for gender identity:
The purported threat that gender-identity protections pose to women in
public restrooms is twofold. The first is rape or sexual assault.
Here, the claim is that predatory men will use these laws to gain
access to their targets by “putting on a dress” and invading the
women’s bathroom.
The second purported threat is rampant
voyeurism -- a threat to women’s privacy or modesty through involuntary
exposure of the body. Here, the claim is that salacious men will use
gender-identity protections to invade women’s bathrooms and lurk
there peeping at women...
Both claims
are incoherent. For the rapist seeking available targets, of what help
could a gender-identity law be? A predator who targets women using
public restrooms would not hesitate to enter because a rule tells him
he is not allowed.
In order for these sexual predation claims to make sense, one
would have to posit that predators would lurk in public restrooms for
extended periods of time, hoping for a chance to assault a target.
Lurking is not a protected activity, whatever the gender identity of
the lurker—the enactment of gender-identity protections would not
authorize such behavior.
Aspiring voyeurs likewise have no right to lurk in
bathrooms or otherwise use them for inappropriate purposes, and a post
hoc assertion of gender identity would not provide a voyeur with any
protection—a proposition made explicit in the Connecticut legislation,
which requires a showing that “gender-related identity is sincerely
held, part of a person’s core identity or not being asserted for an
improper purpose.”
It is also argued that exploits are not happening where these laws have already been introduced.