GINSBURG, J., delivered the opinion for a unanimous Court.
This case concerns the consequences of a state trial court’s erroneous denial of a defendant’s peremptory challenge to the seating of a juror in a criminal case. If all seated jurors are qualified and unbiased, does the Due Process Clause of the Fourteenth Amendment nonetheless require automatic reversal of the defendant’s conviction?
Following a jury trial in an Illinois state court, defendant-petitioner Michael Rivera was convicted of first-degree murder and sentenced to a prison term of 85 years. On appeal, Rivera challenged the trial court’s rejection of his peremptory challenge to venire member Deloris Gomez. Gomez sat on Rivera’s jury and indeed served as the jury’s foreperson. It is conceded that there was no basis to challenge Gomez for cause. She met the requirements for jury service, and Rivera does not contend that she was in fact biased against him. The Supreme Court of Illinois held that the peremptory challenge should have been allowed, but further held that the error was harmless and therefore did not warrant reversal of Rivera’s conviction. We affirm the judgment of the Illinois Supreme Court.
The right to exercise peremptory challenges in state court is determined by state law. This Court has “long recognized” that “peremptory challenges are not of federal constitutional dimension.” United States v. Martinez-Salazar, 528 U.S. 304, 311, 120 S. Ct. 774, 145 L. Ed. 2d 792 (2000). States may withhold peremptory challenges “altogether without impairing the constitutional guarantee of an impartial jury and a fair trial.” Georgia v. McCollum, 505 U.S. 42, 57, 112 S. Ct. 2348, 120 L. Ed. 2d 33 (1992). Just as state law controls the existence and exercise of peremptory challenges, so state law determines the consequences of an erroneous denial of such a challenge. Accordingly, we have no cause to disturb the Illinois Supreme Court’s determination that, in the circumstances Rivera’s case presents, the trial court’s error did not warrant reversal of his conviction.
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