In Johnson v. Arteaga-Martinez, the Supreme Court held that a state court’s decision to deny postconviction relief on an ineffective assistance of counsel claim is not entitled to deference under the Antiterrorism and Effective Death Penalty Act (AEDPA). The petitioner in this case was convicted of murder and sentenced to life imprisonment without parole. He later filed for postconviction relief, alleging his trial attorney had provided ineffective assistance by failing to investigate or present mitigating evidence at sentencing. The state court denied his petition without holding an evidentiary hearing or making any factual findings regarding whether counsel's performance fell below professional standards. On appeal, the Supreme Court found that AEDPA did not apply because there were no “adjudicated facts” from which it could determine whether reasonable jurists would disagree with the lower court's conclusion about counsel's performance; thus, de novo review was appropriate instead of AEDPA deference. Ultimately, the Supreme Court remanded for further proceedings consistent with its opinion so that a determination can be made as to whether petitioner received effective representation during sentencing proceedings

In the dissenting opinion of Johnson v. Arteaga-Martinez, Justice Thomas argued that the majority opinion was wrong in its interpretation of the Immigration and Nationality Act (INA). He argued that the majority opinion failed to consider the plain language of the INA, which states that an alien who has been convicted of an aggravated felony is ineligible for discretionary relief from removal. Justice Thomas argued that the majority opinion's interpretation of the INA was too broad and that it should be limited to the plain language of the statute. He argued that the majority opinion's interpretation of the INA would lead to absurd results, such as allowing an alien who has been convicted of an aggravated felony to remain in the United States despite the fact that the INA clearly states that such an alien is ineligible for discretionary relief from removal. Justice Thomas concluded that the majority opinion's interpretation of the INA was wrong and that the plain language of the statute should be followed.