when they are wearing a uniform, as male politicians essentially do.

as引导比较分句，表示“正如/就像...那样”之意。

类似的句子：

He goes to work by bus, as most people do.

She is beautiful, as her sister is.

通常认为as为连词，在从句中不作成分。其实，如果仔细分析的话，我们会发现其实as在引导从句的同时，还是在从句中作成分的。(第一句中，as为do的方式状语，第二句中as为表语。）