Julia Letlow and former congressman John Fleming will square off for the Republican runoff to win Louisiana's U.S. Senate seat.
The race picks a successor to retiring Senator Bill Cassidy.
Letlow has the support of former President Donald Trump.
Fleming says he is a contender to the Trump‑backed candidate.
Voters have observed both candidates travel across the state.
The contest will demonstrate how much sway Trump still has with Louisiana GOP voters.
The runoff determines who will hold in the Senate next.