As CPT Rainey is aware, given she wrote an article about it for Special Operations Forces Report (SOFRP), servicemember’s don’t surrender all First Amendment rights. The ban against political activities, generally speaking, applies to participating in partisan activities while wearing the uniform. (If you want a more detailed explanation of the do’s and don’ts for active-duty personnel, I suggest reading CPT Rainey’s excellent article.)
Thus, there’s an interesting legal question for her and other service-members—is there liability merely for showing up to the rally? Would a court-martial convict an officer under Article 133, UCMJ, for conduct unbecoming; or under Article 134, for engaging in service-discrediting activity, or conduct prejudicial to good order and discipline? And if not a court-martial, is mere participation at the rally grounds for separation or a letter of reprimand? Or would all of these actions violate the servicemembers’ constitutional rights to freely associate and speak?
While I have an opinion about the constitutionality or wisdom of pursuing such disciplinary actions in those circumstances, I won't share it here. What I do predict, though, is that all rally-goers need to be prepared for adverse action regardless of their level of participation. And I expect, given the publicity of the events, there will be consequences for many of the participants, even absent clear proof of a criminal act. So there will be litigation on this issue, with no clear resolution for a few years.