Republican front-runner Donald Trump traded jabs with former Florida Governor Jeb Bush, former business executive Carly Fiorina and other presidential candidates in a contentious debate on Wednesday marked by bickering and personal attacks.In the second debate of the 2016 Republican White House race, the candidates also condemned President Barack Obama's nuclear deal with Iran, but differed on what they would do with the contested accord if elected.Ted Cruz, a US senator from Texas, said the nuclear deal with Iran should be ripped up, but Paul said it should be enforced because Congress had not been able to stop it.
