Spotlight: U.S. partisan confrontation heats up over Iran deal

The newly reached Iran nuclear deal has caused a heated confrontation between Democrats and Republicans, especially among their candidates for the 2016 presidential election.

On Monday, President Barack Obama criticized Republican presidential candidates Mike Huckabee and Donald Trump for their blunt rhetoric about the nuclear deal, dismissing their attack as "ridiculous if it weren't so bad."

"The particular comments of Mr. Huckabee are, I think, part of just a general pattern that we've seen that... would be considered ridiculous if it weren't so sad," Obama said during his visit Ethiopia. He also described the former Arkansas governor's remarks as emblematic of a slide in Republicans' public speeches.

Huckabee on Saturday denounced the Iran deal, saying Obama is marching Israelis "to the door of the oven," a reference to the Nazi gas chambers that killed millions of Jews in the Holocaust.

Earlier, Trump called the deal "a disgrace," saying the United States "should have doubled up the sanctions" on the Islamic Republic over its nuclear program. "We were dealing from desperation," he said in an interview with the U.S. media MSNBC.

Republican candidates are united in their opposition to the deal, saying Obama has left Iran on the brink of building a bomb and done nothing to address Tehran's support for terrorism. Some, including Wisconsin Governor Scott Walker and Florida Senator Marco Rubio, have vowed to immediately scrap the agreement if elected.

The White House has intensified a lobbying campaign to make the deal get through Congress. Lawmakers have until mid-September to review the accord, which aims to curb Iran's nuclear program in exchange for relief from international economic sanctions.

Obama's comments marked his most direct engagement in the race to succeed him. His unsparing criticism on Monday underscored his sensitivity to efforts to scuttle the Iran accord, which he hopes will be his signature foreign policy initiative. It also raised the prospect of an aggressive role for Obama in the 2016 presidential campaign.

"In 18 months, I'm turning over the keys," Obama said. "I want to make sure I'm turning over the keys to somebody who is serious about the serious problems that the country faces and the world faces."

Rebutting Obama's criticism, Huckabee said in a written statement "What's 'ridiculous and sad' is that President Obama does not take Iran's repeated threats seriously."

"For decades, Iranian leaders have pledged to destroy, annihilate, and 'wipe Israel off the map' with a 'big Holocaust.'"

Presidential candidate Hillary Clinton, the front-runner for the Democratic nomination, on Monday also said she found Huckabee's remarks offensive, claiming that his remarks should be "repudiated by every person of good faith."

"One can disagree with the particulars of the agreement to put a lid on the nuclear weapons program of Iran, and that is a fair game. But this steps over the line," Clinton said during a campaign stop in Iowa.

However, experts said that although Republican lawmakers are furious over the deal with Iran and even if Congress votes down the deal, it will be extremely difficult to repeal it.

"It will be very difficult to get the world community to re-impose economic sanctions on Iran," Brookings Institution's senior fellow Darrell West said of the harsh economic sanctions that many analysts believe played a major role in getting Iran to come to the negotiation table in the first place.

Indeed, it was no easy task for Washington to get Western countries to agree to sanctions that would prevent Iran from selling oil to Europe, and convincing them to do so again would be an uphill battle if they could be convinced at all, analysts said. Endi