Welcome to Supreme Court Brief. The high court wrapped up its first week of oral arguments of the January session on Wednesday, putting just one more weekly conference between the justices and their three-day holiday weekend because of Martin Luther King Jr.'s birthday.

The court convened for just one case on Wednesday: Smith v. Arizona, which asks whether Arizona prosecutors violated a drug defendant's Sixth Amendment right to cross-examine the witnesses against him when they called a "substitute expert" to the stand to talk about another expert's forensic testing. 

Today's Brief discusses the pushback Arizona Principal Deputy Solicitor General Alexander Samuels faced for making an argument that some justices suggested may have been "forfeited below."