DoD DIRECTIVE 1344.10
b. A member on AD shall not:
(1) Use his or her official authority or influence for interfering with an election; affecting the course or outcome of an election; soliciting votes for a particular candidate or issue; or requiring or soliciting political contributions from others.
(2) Be a candidate for, or hold, civil office except as authorized in subsections D.2. and D.3., below.
(3) Participate in partisan political management, campaigns, or conventions.
(4) Make campaign contributions to another r of the Armed Forces or an employee of the Federal Government.
DITTO. It also violates Government Ethics Guidelines. You cannot use your position or wear a uniform to connotate officialdom to solicit customers, support of a cause or product, etc, unless it is official business (ie recruiter, advocate for a military program, etc). Electioneering is not official business.