In the 2016 case Lee v. United States, the Supreme Court ruled in favor of Jae Lee, a South Korean immigrant who had been living in the U.S for over three decades. The issue at hand was whether Mr. Lee's attorney provided ineffective counsel by incorrectly advising him that pleading guilty to drug charges would not result in his deportation. After being charged with possession of ecstasy with intent to distribute, Mr. Lee followed his lawyer’s advice and pleaded guilty hoping to avoid deportation; however, this led directly to his mandatory removal from the country under immigration law due to it being an aggravated felony conviction. Mr.Lee appealed on grounds of ineffective assistance of counsel as guaranteed by Sixth Amendment rights arguing that he only pleaded guilty because he was misinformed about its consequences on his immigration status. The Supreme Court agreed stating that even though evidence against him was strong and likely would have resulted in a similar outcome after trial but given different advice regarding plea deal implications for deportation - there is reasonable probability he would have risked going trial instead.

In the dissenting opinion for Lee v. United States, Justice Thomas, joined by Justice Alito, argued that a defendant must demonstrate prejudice to establish an ineffective assistance of counsel claim under Strickland v. Washington (1984). They believed that Jae Lee failed to show he was prejudiced by his attorney's incorrect advice about deportation consequences following a guilty plea because even if he had gone to trial instead of pleading guilty, there was overwhelming evidence against him and it would have resulted in conviction and mandatory deportation anyway. The majority’s decision focused on the outcome of a hypothetical scenario where Lee did not plead guilty but went to trial instead; however, Justices Thomas and Alito contended this approach ignored Strickland's requirement for defendants to affirmatively prove bias resulting from their counsel's performance.