Senator Marco Rubio of Florida was hammered as callow, ambitious and lacking in accomplishment during the Republican presidential debate here on Saturday night, as Gov. Chris Christie of New Jersey led an all-out assault to try to halt Mr. Rubio's growing momentum ahead of the critical New Hampshire primary on Tuesday.
Mr. Rubio, facing the fiercest attacks yet of the Republican race after his strong third-place finish in the Iowa caucuses, looked rattled at times and faltered as he pushed back with scripted lines about President Obama that Mr. Christie mocked mercilessly.
Former Gov. Jeb Bush of Florida and Donald J. Trump also pounced on Mr. Rubio, whose rising popularity in New Hampshire poses a grave threat to their candidacies.
Mr. Christie was pugnacious from his first statement, while Mr. Bush mixed ridicule - mostly aimed at Mr. Rubio - with sobering lectures, fighting about his policy ideas on missile defense and eminent domain.