online currency bitcoin can basically be used for various transactions. For example, for legal transactions such as wordpress.com, Galatic virgin airways, republikhost.com, and various social donations like to wikileaks.
On the other hand, the digital currency can be used for the benefit of a greater portion of illegal internationally. Illegal acts that include money laundering, gambling, drugs, and even protitusi.
But it is possible if in the U.S. ensued with bitcoin money laundering. If there are politicians who commit this crime, the police will be very difficult to handle. Unless, if they cooperate with or exchanher bitcoin users who understand the concept of bitcoin
I don't think that it is nearly as easy for politicians in the US to hide money as you seem to think it is. Their finances are fairly public and moving large amounts in and out of bitcoin exchanges isn't going to help them evade the public eye as much you think.
If you mean that they could take corruption payments directly in bitcoin, then yes, I see what you mean there. That does make it easier for them. But even so they still have to cash it out somehow, or buy things with the bitcoin. Or they could hold bitcoin if they felt that it was a sound investment.
All and all, it's not much different than cash. A corrupt politician could accept a briefcase full of cash and have the same problems washing it as he would with washing the bitcoins he would receive instead. Also, using bitcoins requires a little bit of technical familiarity and a lot of the US politicians are well known for being technically inept.
The biggest challenge of laundering money with bitcoin is moving it into and out of fiat. It is very easy to have bitcoin that you control not be associated with previous transactions but is much more difficult to exchange it for fiat without raising any kind of red flag