D.C. Mun. Regs. tit. 4, r. 4-515
An employer, other than a political organization, shall not discharge, refuse to hire, or otherwise discriminate against an employee with respect to employment because of the employee's present or past political affiliation or lack of political affiliation.
Mere membership in a political party having unlawful goals shall not suffice to justify discrimination in employment unless that prohibition is required by federal or District law.
An employer shall not retaliate against an employee for failure to vote for a designated candidate. This shall not prevent an employer or employee from expressing support for any candidate unless prohibited under federal or District civil service laws.
An employer shall not require employees to contribute to fundraising campaigns of any political party or candidate or to provide any type of support for any political party or candidate.
D.C. Mun. Regs. tit. 4, r. 4-515