Senate Republicans voted against a Democratic bill that would have required President Trump to obtain congressional authorization to continue waging war against Iran.
Homeland Security Secretary Kristi Noem pushed back against her department's inspector general, who told Congress in a letter that she had "systematically obstructed" his office's work.
The Associated Press had not yet called the race. The contest was widely viewed as a bellwether for the type of candidate that Democratic voters wished to elevate in the Trump era.
Nearly every Republican voted to block a measure that would require that President Trump win authorization from Congress to continue the offensive in the Middle East.