The U.S. Supreme Court has rejected Arizona’s request to let its proof-of-citizenship requirement for people registering to vote remain in effect as it appeals a ruling that found the mandate conflicts with federal law.

A lower court had ruled in April that a federal voting law trumps Arizona’s requirement.

Earlier this month, one Supreme Court justice granted the state’s request to let the requirement remain in effect while Arizona appealed the April decision.

But the full court on Thursday rejected the request.

Arizona’s lawyers had argued that the requirement ought to remain in effect because there’s a reasonable probability that the court will agree to hear its appeal and reverse the lower court’s decision.

Opponents consider the requirement to be a constitutional violation.

Senior Editor, News, Arizona Daily Star, Tucson, Az.