This only applies in the United States.
Our department is currently hiring a new faculty member. At the moment, the faculty gender ratio in our department is very skewed, even for our field. I believe that this has a negative impact on the department environment.
It is illegal to consider gender. You could find that if a man were hired, they would alter the environment in the same way you are imagining a woman would. What should matter is whether or not prior or existing hiring practices were/are discriminatory, which resulted in a skewed gender ratio. For example, it can be illegal to hire by word of mouth if that method results in an all male or all female environment. Did you put the desire to alter the departmental environment in your advertisement for the position? If you did, then people of both genders would respond on how they have skills to do that. If someone has certain skills that were not advertised for you cannot assume the others lack them if they do not believe they are supposed to show the skill. Are you hiring based on criteria you did not place in the ad?
This candidate is highly qualified in terms of her research and teaching. Moreover, among all the candidates who have visited, she is the only one who has any experience with diversity initiatives and getting underrepresented groups into STEM. This is very important to many of us, especially since the department is planning to add an undergraduate program in the near future.
This is an appropriate reason to support a candidate if you placed in the advertisement. If you have an ad that says we are hiring based on X, Y, Z and you support them because of A, then you may have a problem. Did you ask the other candidates if they had experience in this? They may, but may have felt it not relevant to the advertised job. In Watson vs Fort Worth Banking and Trust, the court held that if discretionary criteria were used then suit could be brought under equal employment laws if there was a disparate impact. This sounds like disparate impact to me but in the opposite direction of usual enforcement.
We are planning to write an open letter to the department in support of this candidate, citing her qualifications as someone who has worked to make science a more inclusive place for women and other underrepresented minorities.
Also appropriate, although weird. By the nature of an open letter, it is open, which means it can be used by losing candidates in lawsuits for improper hiring practices.
My main question is is whether it is appropriate for us to additionally express our desire for a woman faculty member.
It is illegal for anyone with the power to consider a candidate's appropriateness to consider gender. If you are considering gender and you have a vote, then you are in violation of US civil rights and employment laws.
When I say something like "we think the department should hire a woman", I don't strictly mean that the next faculty should be a woman regardless of any other factors. Rather, I mean that the department should hire someone who will be able to relate to the issues women face in academia and STEM, and help champion female students in our department. The average woman will be in a better place to do this than the average man, so perhaps I should have been a bit more precise about what I meant in the original post.
This is gender discrimination. The illegal assumption is that men are unable to relate to women and their issues. It is not legal to assume that a woman can do something better than a man or a man better than a woman. You are confusing skill and knowledge with gender. You are assuming that men are unaware of their environment or the work or professional issues women face. You are also assuming they cannot encourage women into STEM. The US Department of Education is investigating complaints on this under Title IX currently.
While "diversity programs" designed to get underrepresented minorities into stem are discriminatory in the strictest sense of the word, they are in place to address systemic injustices which have existed for a very long time. The hypothetical examples of discriminating against men and women don't account for the fact that many gender/race imbalances in academia exist because of previous institutional discrimination.
In Wards Cove Packing Co. v Antonio, the court ruled that you cannot consider the cumulative effect of past practices, but only specific policies. So if discrimination existed in the past resulting in a current imbalance, then prior women who were not hired may file suit, but it is against the law to now discriminate to fix a prior policy. Affirmative action for students comes under a very different legal structure than employment discrimination and rely on different parts of the legal code.