In the case of Torres-Valencia v. United States in 1983, the petitioner, a Colombian national and resident alien in the U.S., was convicted for conspiracy to distribute cocaine. The Supreme Court had to decide whether or not his conviction should be overturned due to an alleged violation of his Sixth Amendment right - specifically, that he was denied effective assistance of counsel because his attorney failed to file a notice of appeal despite being instructed by him to do so. The Supreme Court ruled against Torres-Valencia. They held that even though there may have been negligence on part of the defense attorney, it did not necessarily mean that this resulted in ineffective assistance under constitutional standards. The court reasoned that since Torres-Valencia could not show any specific prejudice resulting from this failure (i.e., he couldn't prove how filing an appeal would have changed anything), then no Sixth Amendment violation occurred. This decision reinforced previous rulings stating that defendants must demonstrate actual harm caused by their lawyer's mistakes before they can claim ineffective assistance.

In the dissenting opinion for Torres-Valencia v. United States, Justice Brennan argued that the majority's interpretation of the statute was incorrect and overly broad. He contended that Congress intended to punish only those who knowingly transport illegal aliens within the country, not merely those who arrange transportation without knowledge of their passengers' legal status. Furthermore, he criticized the majority for failing to consider legislative history in its decision-making process. According to him, this oversight led them to misconstrue Congressional intent and apply an unjustifiably harsh punishment on someone whose actions did not warrant such a severe penalty under existing law as it should be properly interpreted.