What is the meaning of `Beltway politics’?

In American English the word `beltway’ is used to refer to a road which goes around a city or town — what we in India call a `ring road’. The `beltway’ referred to in your question is the road that goes around Washington D. C., the capital of the United States. Beltway politics is normally used to talk about the dirty politics that goes on in Washington.

Source: The Hindu ‘Know Your English’ Series, January 2, 2006