Why is "District of Columbia's at-large congressional district" trending?

Wikipedia Overview

The District of Columbia's at-large congressional district is a congressional district encompassing all the District of Columbia, the federal district of the United States. Article One of the United States Constitution instructs that only "States" may be represented in the United States Congress. Because the District of Columbia does not meet that criterion, the member elected from the at-large district is not permitted to participate in votes on the floor of the House. Instead, constituents of the seat elect a non-voting delegate to the chamber. Though the delegate lacks full voting privileges, they are permitted to sit on, cast votes in, and chair congressional committees and subcommittees. The delegate may also join party caucuses, introduce legislation, and hire staff to assist with constituent services.