Was this on reservation land?
When you drive on a suspended license, there are a number of theories under which your car might be searched. As an inventory prior to an impound, for one. To attempt to locate paperwork such as insurance, ID or registration can be another reason.
If incriminating evidence was found, your attorney can seek to have it suppressed if he can. If you are just mad about the search, then you can do two things: One, get a valid driver's license; and, two, don't drive onto that casino property again.