An almost constant stream of protesters interrupted Donald J. Trump’s nighttime rally here Friday, often resisting removal and dropping to the ground as security personnel tried to hustle them from the event.

Almost every Trump rally has attracted protesters, but on Friday night they practically overtook the event, and “Get ’em out of here” sometimes felt like Mr. Trump’s most repeated line.

“This is a wild evening,” Mr. Trump said halfway through his rally on the eve of the Louisiana primary. “This is one hell of a way to spend a Friday evening.”

The protests started early, as the sun dropped low in the sky and cast a purplish gloaming haze on the rally in an airport hangar, and continued as the night turned slate black.