At a news conference Monday, Obama condemned the likes of Donald Trump, Mike Huckabee and Ted Cruz over what he called "ridiculous" claims about his policies and "outrageous attacks" that crossed the line of political decorum.

From The Guardian:

"Part of what historically has made America great is, particularly when it comes to foreign policy, there's been a recognition that these issues are too serious, that issues of war and peace of such grave concern and consequence, that we don't play fast and loose that way," Obama told reporters.

"We have robust debates, we look at the facts, there are going to be disagreements. But we just don't fling out ad hominem attacks like that because it doesn't help inform the American people."

The outburst was prompted by a question about Mike Huckabee's claim that the Iran nuclear deal would "take the Israelis and march them to the door of the oven".

But Obama argued the problem was more than just a disagreement over this current deal and singled out similar comments by Arkansas senator Tom Cotton and Ted Cruz, the Texas senator and 2016 candidate. "The particular comments of Mr Huckabee are I think part of just a general pattern we've seen that would be considered ridiculous if it weren't so sad," he said.

"We've had a sitting senator call John Kerry Pontius Pilate. We've had a sitting senator who also happens to be running for president suggest that I'm the leading state sponsor of terrorism. These are leaders in the Republican party."