If government counsel in a criminal suit is allowed to inflame the jurors by irrelevantly arousing their deepest prejudices, the jury may become in his hands a lethal weapon directed against defendants who may be innocent.  He should not be permitted to summon that thirteenth juror, prejudice.  Those observations made over 70 years ago were recently recited by Justice Sotomayor when she criticized a federal prosecutor's similarly charged racial remarks.
In U.S. v Calhoun, the federal prosecutor asked an African American defendant on cross examination – you've got African Americans, you've got Hispanics, you've got a bag full of money.  Does that tell you – a light bulb doesn't go off in your head and say, this is a drug deal?  Not surprisingly, the AUSA doubled down on his racial theme when he argued to the jurors in his summation.  He again discussed African Americans and Hispanics in a hotel room with money.  What does your common sense tell you that these people are doing in a hotel room with a bag full of money, cash?  None of these people are Bill Gates or computer magnates or real estate investors.
Notwithstanding the Court's denial of the petition for a writ of certiorari, Justice Sotomayor was direct and pointed in her rejection of the prosecutor's comments.  There is no doubt that the prosecutor's questions never should have been posed – the Constitution prohibits racially biased prosecutorial arguments.  The Justice condemned the attempt to substitute racial stereotype for evidence and racial prejudice for reason.
Not surprisingly, jurors have exhibited similar reliance on racial bias in returning guilty verdicts against people of color.  For example, in Wisconsin, one juror stated, let's be logical – he's black and sees a seventeen year old white girl – I know the type.  Another juror in New Hampshire inferred causation stating, I guess we're profiling but they cause all the trouble.  
Last week, the Supreme Court in Pena-Rodriguez v. Colorado, reversed a conviction finding an exception to the no impeachment rule to a jury's verdict.  Post verdict interviews of some of the jurors recited the racially biased remarks of another juror: Mexican men have a bravado that cause them to believe they can do whatever they wanted with women – I think he did it because he's Mexican and Mexican men do whatever they want – 9 out of 10 times Mexican men were guilty of being aggressive toward women and young girls – alibi witness not credible because he was illegal.
Justice Kennedy in Pena-Rodriguez recognized that racial bias, left unaddressed, causes systematic injury to the administration of justice. 
Defenders must remain vigilant against the attempts of prosecutors and juries to convict people of color using a lower standard of proof.  We cannot allow prosecutors to question or suggest or argue that because someone is African American or Hispanic, he must be a gangbanger or a drug dealer.  Criminal defense attorneys must hold the government accountable.  The government must prove facts, not rely on juror bias or racial reasoning to complete the prosecution's narrative.
We must push back against those traditional excuses that the question, argument or comment in deliberation was isolated and thus, harmless error.  We need to educate trial judges through in limine applications, requests for additional voir dire (ideally in person), supplemented with detailed jury selection questions on racial beliefs, defense specific requests to charge, objections to prosecutor's questioning and arguments not merely as improper or burden shifting, but as directly contravening the defendant's right to a fair trial under the Sixth Amendment.  We cannot merely sit down after the glazed look from the trial judge overruling our objection or exception to the Court's instruction.  We must be prepared to explain why racially biased arguments cultivate bias in the jury offending the defendant's right to an impartial jury.
Justice Kennedy's words provide a foundation for arguing why these special requirements are necessary:
All forms of improper bias pose challenges to the trial process.  But there is a sound basis to treat racial bias with added precaution.  A constitutional rule that racial bias in the justice system must be addressed – including, in some instances, after the verdict has been entered – is necessary to prevent a systemic loss of confidence in jury verdicts, a confidence that is a central premise of the Sixth Amendment trial right. [Pena-Rodriguez v. Colorado, 580 US ___, (decided March 6, 2017)].
We may not successfully exclude all racial animus from our trials, but hopefully, we will have more success prohibiting the prosecution from summoning that thirteenth juror.