Senator Marco Rubio, alarmed by Donald J. Trump’s ascendancy and worried that his presidential chances were slipping away, unleashed abarrage of attacks on the real estate mogul’s business ethics, hiring practices and financial achievements in Thursday’s debate, forcefully delivering the onslaught that Republican leaders had desperately awaited.
In a series of acid exchanges, a newly pugnacious Mr. Rubio, long mocked for a robotic and restrained style, interrupted Mr. Trump, quizzed him, impersonated him, shouted over him and left him looking unsettled. It was an unfamiliar reversal of roles for the front-runner, who found himself so frequently the target of assaults from Mr. Rubio and Senator Ted Cruz that he complained they must have been a ploy for better television ratings.
From the opening moments of the debate, Mr. Rubio pounced. Deploying his own up-by-the-bootstraps biography, the Florida senator assailed Mr. Trump for hiring hundreds of foreign workers at his tony resort in Florida and passing over Americans who had applied for the same jobs.
“My mom was a maid in a hotel,” Mr. Rubio said. “And instead of hiring an American like her, you’ve brought over 1,000 people from all over the world to fill in those jobs instead.”
Moments later, Mr. Rubio moved to cast Mr. Trump as a huckster who outsourced the manufacturing of the clothing that bears his name to countries like Mexico and China even as he promised to wage a trade war against those countries.
When Mr. Trump tried to protest, Mr. Rubio interrupted right back.
“Make them in America!” he demanded.
The acerbic and urgent tenor of the exchanges reflected the panicked state of a Republican field determined to halt Mr. Trump, whose crudely freewheeling style, abundant self-assuredness and durable popularity have produced three consecutive early-state victories that threaten to put the nomination out of reach for his two biggest rivals, Mr. Rubio and Mr. Cruz.
The two-hour rumpus frequently devolved into unmediated bouts of shouting, name-calling and pleas to the moderators for chances to respond to the latest insult.
“This guy’s a choke artist,” Mr. Trump declared, pointing to Mr. Rubio. “This guy’s a liar,” he said, swiveling toward Mr. Cruz.
The timing of Thursday’s debate in Houston, days before 595 delegates are awarded in voting across the country on March 1, made it among the most anticipated and consequential debates of the Republican campaign season and the first to feature a shrunken field of five candidates.
After resounding defeats at the hands of Mr. Trump in the past two primaries, both Mr. Rubio and Mr. Cruz walked onto the stage confronting treacherous paths ahead and a pressing dilemma: whether to keep trying to destroy each other, their comfort zone in past debates, or to aim their fire at Mr. Trump.
They chose war with Mr. Trump. But amid the relentless back and forth, a question hovered: Was it too late