The T in LGBT
Transgender people have been the step-children in the LGBT community. The notoriety of the HB-2 law in North Carolina and the pending legislation in Texas about so-called "bathroom bills" brought them out of the dark into public consciousness. In spite of all the mean-spirited bigotry associated with this publicity, it brought about the unintended consequence of making them visible.
The Twitter edict by the Donald took the abuse a step further in mandating the exclusion of transgender people from the military. The same excuse was used as was used against gays and lesbians that they would hinder combat readinaess. When that issue was raised in the Obama administration, the military took a long time and studied the impact and concluded that allowing LGBT people to serve openly would not create a negative impact. They even spent considerable time and effort in diversity training and surveys to mitigate the transition from the prior exclusionary policies.
After Trump posted one of his infamous tweets, the Defense Department responded that the expulsions would not take effect until a new formal written policy was received from the White House. Those transgender people currently serving in the military would be allowed to remain on active duty until further notice. The White House has since then stitched together a plan that would require them to be phased out over time.
A statement was released by the Palm Center from 56 retired general and flag officers responding to President Trump’s proposed ban on transgender service members in the U.S. military. In their statement, the retired officials stated that such a ban could cause “significant disruptions, deprive the military of mission-critical talent, and compromise the integrity of transgender troops who would be forced to live a lie, as well as non-transgender peers who would be forced to choose between reporting their comrades or disobeying policy.”
This one tweet stirred the pot of hostility and dissension all over again, which in itself will have an impact on military readiness. The Department of Defense just went through this exercise, and now they may have to go through it all over again if Congress or the courts don't act.
The move was a calculated political step to appeal to Trump's base that are mostly homophobic and/or racists. His appeal to the dark side is one of the tactics that helped get him elected, and he is still operating in campaign mode rather than serving as President.
Transgender people of color, both inside and outside the military, already have been particularly vulnerable to harassment and violence. Trump's action only increases that proclivity among some people.