What does Beltway wisdom mean?

Beltway wisdom meaning in Urban Dictionary

Ironically-named, out-of-touch nonsense repeated in an echo chamber by specialists in politics and/or media just who reside in the Washington DC metro location, often proven wrong since the insulated people who donate to it tend to be obsessed with horserace politics, their particular Twitter reports, their ipads, and their beverage parties instead of talking about the real problems that affect People in the us that don't live there