Republican presidential hopeful Marco Rubio has attacked Donald Trump for saying that Islam hates America, in a televised debate in Miami.
Mr Rubio, who faces a do-or-die contest in Florida on Tuesday, said Islam had a problem with radicalisation but said that many Muslims were proud Americans.
“Presidents can’t just say whatever they want. It has consequences,” he said, to cheers from the audience.
The four Republicans heeded pleas from party leaders to have a civil debate.
Unlike in the last TV event, which was littered with personal insults, this one was more substantive with a focus on policy.
“So far, I cannot believe how civil it’s been up here,” Mr Trump observed at one point.
But on the issue of Islam, there was clear distance between Mr Trump and the others. Mr Trump stood by comments he made earlier in the day when he said “Islam hates us, there’s a tremendous hatred”, and railed against political correctness.
But Mr Rubio said: “I’m not interested in being politically correct. I’m interested in being correct.”
All three of Mr Trump’s rivals distanced themselves from Mr Trump’s statement in December that in the fight against terrorist “you have to take out their families”.
“We’ve never targeted innocent civilians and we’re not going to start now” Mr Cruz said.
When Mr Trump was challenged on the legality of targeting civilians, he said that America had to be able to fight on “an equal footing”.
“We have to obey the laws, but we have to expand those laws”, he said.
On Tuesday five large states will vote for presidential candidate in each party, with Ohio Governor John Kasich and Mr Rubio, a Florida senator, under pressure to win their home states.