I answered your question. There is no white caucus because whites control everything.
Policy, education, what we are told about history, how we are to act if we are "civilized", all of that has been determined in North America for the past 300 years by whites.
There is a black caucus to bring another point of view to the table. To represent all the people who are not like you.
You do not realize that you have that privilige because of the privilege itself. You have an racially social advantage if your skin is white. You see your likeness reflected back on tv, in the movies, in magazines in books, and never think twice about it. Not so for other races. You think every American shares the experiences that you do, and that is not the case. You can move anywhere in the country that you choose (if you have the money), and that is not true for everyone. You don't have to worry that your neighbors will dislike or distrust you for the color of your skin. When your kid reads a history book in school, you do not have to deal with the emotional impact of dealing with hate words, such as savage, infidel, or squaw. You don't have to deconstruct the historical lies that American children are taught about the beginnings of this country (had to do this tonight with my 16 year old and it HURTS!). You can be successful, without people thinking you are such a good role model for other (insert ethnicity/race). Noone thinks you got into school or got your job thru affirmative action instead of high grades/work.
Anyway, what I am getting at is that there is white caucus in Washington. There is very little representation for those of us in a racially socially disadvantaged state.