In the case of Stephen Danforth v. Minnesota, 2007, the U.S. Supreme Court ruled that state courts are not constitutionally required to apply new federal constitutional rules retroactively in post-conviction proceedings. The petitioner, Stephen Danforth was convicted for sexual assault and argued his Sixth Amendment rights were violated because a videotaped interview with the victim was played at trial without allowing him to cross-examine her. While his appeal was pending, the Supreme Court decided in Crawford v Washington (2004) that such testimonial evidence is admissible only if defendants have an opportunity to cross-examine witnesses against them or if those witnesses are unavailable and defendants had prior opportunities for cross-examination. However, when he sought relief based on this ruling from Minnesota's courts they denied it stating that Teague v Lane (1989), which generally bars retroactive application of new procedural rules in federal habeas cases applied here as well . The U.S Supreme court disagreed holding states can give broader effect than required by Teague’s non-retroactivity principle under their own laws.

In the dissenting opinion for Stephen Danforth v. Minnesota, Justice Anthony Kennedy argued that allowing states to apply federal constitutional rules differently than the Supreme Court would undermine uniformity and lead to confusion in law enforcement and courts across different jurisdictions. He emphasized that it is crucial for a single, national interpretation of federal law to exist so as not to create disparities between states' interpretations. Furthermore, he expressed concern over potential misuse of this power by state courts who might use their newfound authority selectively or inconsistently. Ultimately, he believed that granting such discretion could weaken the role of the Supreme Court as final arbiter on matters concerning federal constitutionality.