@Needmoresleep and @nauticant
Too many state laws protecting gender identity, with the cultural acceptance that goes with it. Bad here. Worse over there.
It depends on how you look at it I think.
Cultural acceptance is grand or non-existent depending on where you look. The US is an individualist society/culture like the UK but US is beginning to lean more collectivist. Because the US is a country born of immigrants and is very young there really isn't a bonafide US culture able to be observed consistently from state-to-state or even city-to-city.
Just like everywhere else in the world the loudest voices are heard and many that disagree tend to be meek or less vocal - e.g. my father and stepmother attend a Non-denominational Christian Church which denounces the T but embraces all races/nationalities and LGB, they are kind and meek but fear that the T explosion is a sign of "the end of days"... they do not vilify the individuals but the ideology as it conveys that the creator made mistakes (an impossibility in their eyes, hearts, and minds). While I see the world differently some of my perspective on gender dysphoria is congruent with theirs (the facts, not the ethereal). Many that disagree are silent while the minority believing TWAW and TMAM is loudly in public and quietly in law pushing their agendas.
While in no way shape or form am I a fan of Trump and his antics, but I really appreciate that his administrationrescinded Obama's guidance (not law but guidance in interpretation) on gender identity being protected under 'sex' (Title IX only bars discrimination based on a student’s biological sex under Trump admin interpretation and guidance for enforcement). I don't like Trump but I have to give credit when and where it is due.
20 US states and DC have education anti-discrimination laws explicitly protecting LGBT students; 30 states as well as Puerto Rico and Guam do not have any state protections in place. Some states specifically protect LGB and not T.
Just because those laws are on record doesn't mean that courts will uphold them if challenged.
Federal law provides no protection in education beyond protected classes i.e. Race, Color, Religion or creed, National origin or ancestry, Sex, Age, Physical or mental disability, Veteran status, Pregnancy, Genetic information, and Citizenship.
Public schools are subject to federal anti-discrimination laws as they receive federal funds, but aren't really enforced unless challenged (rare). State laws guide these institutions on how to further uphold protected classes but typically are not enforced until challenged (rarer still).
Religious private education institutions are not subject to anti-discrimination laws in education or employment as long as they don't receive federal funds and are not subject to state anti-discrimination laws as long as they don't participate in state funded voucher programs. They are able to refuse education and employment to anyone (including disabled individuals). If they accept federal funds, they are subject to Title VI of the Civil Rights Act (prohibits discrimination on the basis of race, color or national origin - NOTE sex is not protected). In regards to Title IX, these organizations are exempt “to the extent that application of Title IX would be inconsistent with the religious tenets of the organization”. The majority of private schools in the U.S. are religious, so they have a great deal of wiggle room in regards to all protected classes.
Private (not religious) education institutions are subject to Title IX protections but due to Trump's interpretation guidance as mentioned above sex-based discrimination is only prohibited based on one's biological sex. All-girls/women or all-boys/men schools are exempt from Title IX sex protection and as a result are legally able to restrict their admissions accordingly.
In regards to changing your sex on your birth certificate, most US states have it codified into law - I firmly disagree with this as you are born a sex and should not be able to change your birth records to reflect how you feel even if you had full reassignment surgery. There are other ways to handle fully reassigned individuals without destroying the validity of birth certificates and confusing governmental authorities. The US sends SSA checks to dead people, truly disabled people have problems gaining disability benefits while some abusers are able to gain access, voter fraud is rampant in certain states, and somehow the state and federal governments think they can keep gender identity straight with altered birth certificates in play (yeah right).
Fortunately the US does not have a federal self-ID policy in place and while it appears it's being pushed it does not appear to have gained any traction in legislation (but then again most of this legislation is being codified under the veil of night so I could be wrong).
TLDR; US private sex-segregated schools are legal and exempt from sex anti-discrimination laws (even when receiving federal funds). Morehouse College (under law) has every right to reject students admission whether TW (based on gender identity) or TM (based on sex).