For years, a defendant in Arkansas could not argue entrapment and in the alternative argue that he failed to commit an element of the underlying crime. In other words, the defendant had to choose either that he was entrapped OR that he did not commit the crime. In order to get an entrapment jury instruction, the defendant had to admit he committed the crime.
But that has all changed with the Arkansas Supreme Court's decision in Smoak v. State of Arkansas (http://opinions.aoc.arkansas.gov/WebLink8/0/doc/252565/Electronic.aspx). Now a defendant may defend the underlying charge as well as argue entrapment. A major factor in the decision is the fact that the defendant was required to effectively give up one of his most sacred constitutional rights (that the government must prove its case) as the law currently existed. That anomaly has now been corrected.