The term 'D.C. Insiders' refers to politicians and political operatives who are well-versed in the inner workings of Washington, D.C. and have a deep understanding of the political landscape. The crossword solution for this term is 'POLS, ' which is an abbreviation for 'politicians.' These individuals are typically experienced in the field of politics and have a strong knowledge of the laws, regulations, and procedures that govern the nation's capital.