Can anyone answer a question about the TSA for me? The TSA is a government agency, right?

Why does PDX have a special line for First Class passengers? I can understand why the airlines give preferential treatment to First Class Passengers, but since when does the US government allow people to pay for special treatment?

This bothers me. Like I said, I don’t mind companies doing it, that’s called capitalism, which I am in favor of, but the government is supposed to work the same for everyone.