The Supreme Court won't hear an appeal from an Arizona sheriff seeking to halt President Barack Obama's plan to spare millions of people from deportation.
The justices on Tuesday let stand a lower court ruling that said Maricopa County Sheriff Joe Arpaio had no legal basis to challenge the program.
Arpaio claimed the program would let more immigrants enter the country illegally, creating a burden on law enforcement from increased crime.
A federal judge said Arpaio's complaints were speculative. The federal appeals court in Washington, D.C., agreed.
The high court separately decided to hear another case on Tuesday in which 26 states have challenged the constitutionality of the plan. The federal appeals court in New Orleans last year blocked the program while that lawsuit moves forward.