What does "it" refer to?

Context:

Skilling's original sentence was overturned by the Fifth Circuit back in January 2009. The resentencing was delayed by ongoing litigation between federal prosecutors and Skilling lawyers. In 2010, the Supreme Court held that Skilling did not violate a federal law making it a crime to deprive another person of "honest services." The justices, however, declined to overturn Skilling's conviction and a federal appeals court later ruled that the conviction would stand.