The two most powerful lobbies in Washington, so the town’s old hands will tell you, are the National Rifle Association (NRA) and the American Israel Public Affairs Committee (AIPAC). Members of Congress, not to say presidents, cross them at their peril.

The Obama administration’s lack of interest in gun control is evidence enough of the NRA’s grip on policy. Indeed, when the Democrats took back the House of Representatives in 2006, they openly touted the new pro-gun members they had recruited.

As for AIPAC, I felt I understood everything I needed to know about the organisation the moment I walked into its annual Washington conference last year. The huge event pulses with power, as does its guest list.

Few Washington lobbies could get away with what AIPAC did this year at its annual shindig—have Liz Cheney, the former vice-president’s daughter, denounce Barack Obama’s Israel policies from the podium, only hours before the President came to defend himself.

In 2011, Benjamin Netanyahu lectured Obama in front of the cameras at the White House, and then proceeded to Capitol Hill to criticise the administration in a speech to Congress. In a bitterly polarised polity, no-one seemed to think his criticism was out of place. Indeed, he won a standing ovation from both sides.

Netanyahu was politer at this year’s AIPAC, but Obama was still on the defensive, listing the ways his administration had backed Israel and laying down a series of red lines over Iran, the issue which dominated their meeting.

Just minutes after Obama reassured the AIPAC lobby that, when it comes to Iran “I have Israel’s back”, his leading Republican opponent for 2012, Mitt Romney, went on the  attack. “If Barack Obama is reelected, Iran will have a nuclear weapon and the world will change,” he said.

At about the same time Newt Gingrich, the former House of Representatives speaker, was taking aim at a different but related political target—the rising price of oil, which is partly the result of sanctions placed on the Iranian regime.

Electoral opportunism aside, the comments underline a political trap that is developing for Obama. Since he took office three years ago, Iran has remained one of the most intractable and complex foreign policy issues he has faced. And at precisely the moment various strands of the problem appear to be reaching a crunch point, there is a danger of Iran becoming the wild card in this year’s presidential election.

The President has adopted a range of tactics to prevent Iran from getting a nuclear weapon. Within weeks of taking office, he posted a video on YouTube appealing to the Iranian public, promising a “new beginning” and “constructive ties”. At the same time he was reportedly giving the nod to covert activities aimed at slowing Tehran’s nuclear program, including a range of different attempts to sabotage nuclear activities. He has also put in place by far the toughest sanctions regime the Islamic Republic has faced—a campaign that gathered steam after it was revealed in late 2009 that Iran had built an underground uranium enrichment facility at Fordow, near the holy city of Qom.

Supporters say the policies amount to a sophisticated mixture of carrots and sticks; critics claim that they are incoherent and that the outreach strategy was not given enough time. But whatever the reality, Obama’s Iran policy is reaching a critical stage. On one hand, tensions between the US and Israel are rising. Watching Iran’s advancing uranium enrichment activities, especially at Fordow, many Israeli officials believe the window for taking military action is fast closing, prompting intensifying speculation about an Israeli attack in the coming months. The fact that most estimates suggest such an aerial strike would set Iran back by only a couple of years does not dissuade some in Israel.

The Obama administration sees things very differently. The President points out that Iran has yet to make the crucial political decision to build a nuclear weapon. But an attack now would ensure Tehran decides it definitely needs one, officials say. The many variables make it hard to predict the political impact of any strike. A successful Israeli attack might make Obama look weak, yet he would also be criticised for abandoning an ally if such a venture went badly. Much would also depend on whether the US was sucked into any wider conflict that might break out.

Alternatively, some observers point out that, purely in terms of electoral politics, a US-led attack would yield big benefits. At least in the initial stages of any armed conflict, Americans tend to rally around the flag. Put more crudely, the dirty little secret of US politics is that a strike on Iran could help Obama close to the election.

But veteran political commentator Charlie Cook disagrees, saying any initial support for the President would be fleeting. “This country is so much more partisan, divided and cynical that, whatever rallying around the flag that there was, it would be short-lived,” he says. “I think we are living in a different time now.”