I came across a comment on the Oathkeepers website that explained what they are doing in a nutshell. The comment is anonymous:
"Reasons why I will attend the Oathkeepers Muster:
1. To support the courageous Active Duty servicemen and women and Peace Officers who will be there affirming their oath to support and defend the Constitution.
2. To offer confidence to the American citizenry at-large, that we who have taken our oath to support and defend their Constitutional Rights, will in no way - shape - or form betray that sacred trust.
3. To place on notice, a warning to any officer who might give unlawful orders to his or her subordinates that would violate the Constitutional Rights of the American citizenry, that their actions will not be tolerated; that such orders constitute treason and that prosecution under such charges will be relentlessly pursued.
4. To draw a clear line whereby the government understands its limits, and if it were to violate such, will have broken the supreme law of the land, the Constitution.
5. To let all leaders of government (federal, state, local), military, sheriff and police departments know that there will be no co-operation whatsoever with any illegal or unlawful orders.
6. To remind anyone who would use government force to strip our American citizens of their Constitutional Rights, that history will not be kind to them; that they will be forever branded for the bullies, cowards, and traitors that they are.
See you on the Mall ... so help us God!"