Many individuals in removal proceedings have criminal convictions for which there are no waivers available under immigration law. Aliens conviced of traffcking in controlled substances are often in this situation. In some cases, the immigration attorney may be able to argue that the statute under which the conviction is based is "divisible" and therefore the conviction is not necessarily for trafficking.
If this argument is not successful, the alien seeking relief from removal may require post conviction relief. In seeking post conviction relief, it is necessary to enlist the aid of an experienced criminal attorney who may seek to vacate the conviction based on constitutional errors or find some other basis to have the criminal conviction modified so that it does not compel the alien's removal.