Charlie Rangle In Trouble In The House: What's Wrong With This Picture?

From the New York Post: "A House investigative committee on Thursday charged New York Rep. Charles Rangel with multiple ethics violations, a blow to the former Ways and Means chairman and an election-year headache for DemocratsRead more: http://www.nypost.com/p/news/local/rep_charlie_rangel_will_be_charged_nXvEFTS2kZeySBLghC6DZL#ixzz0uTJqoGxX
The committee did not immediately specify the charges against the Democrat, who has served in the House for some 40 years and is fourth in House seniority. The announcement by a four-member panel of the House ethics committee sends the case to a House trial, where a separate eight-member panel of Republicans and Democrats will decide whether the violations can be proved by clear and convincing evidence. "
I think it's great that the House will be bringing charges against Rangle, one of the most corrupt politicians in our life time.
So, what's wrong with this picture? It is almost impossible to bring charges against a House member, especially when that member is a Democrat and the House is controlled by Democrats.
If the House is able to do that, why hasn't the Department of Justice, led by Eric Holder, been investigating and gotten an indictment against Rangle? It's not because Rangle is a black Democrat politician, is it?