Prime Minister Benjamin Netanyahu drew a torrent of ridicule Thursday when he unveiled before the General Assembly of the United Nations a cartoon bomb and drew a red line on it with a marker he pulled from his pocket.

It was a gimmick that ignited a wave of scorn and “Looney Tunes” jokes on social media sites.

Even some supporters of Israel, such as American journalist Jeffrey Goldberg, bemoaned Netanyahu’s use of the cartoon.

[blackbirdpie url="https://twitter.com/JeffreyGoldberg/statuses/251382943581343744"]

But the image of the Israeli prime minister drawing with a bright red marker before the assembled delegates of the General Assembly — the very scene mocked and belittled by pundits, observers and activists — was not meant for the delegates in the hall, or the journalists on Twitter.

Netanyahu’s speech was not even meant for US President Barack Obama, who may ultimately decide the fate of the Iranian nuclear program.

Instead, Netanyahu was speaking over Obama’s head, directly to the president’s employer and boss: the American voter.

In the wake of his open disagreement with Obama in recent weeks over the timeline for stopping the Iranian nuclear program, Netanyahu has been accused — not least by leading Democratic members of the House of Representatives — of inserting himself into the American presidential election on the side of Republican challenger Mitt Romney.

Netanyahu has argued that the timing for his public calls for an American “red line” on Iran is unconnected to the US “electoral calendar,” but rather is driven by the Iranian “nuclear calendar.” Iran, he argued before the General Assembly, will be able to build a nuclear weapon by next year.

But it was hard on Thursday to listen to Netanyahu’s speech — delivered in English, couched in simple language full of references to the Bible and Jewish history, and accompanied by what may be the most childish prop ever brought into the Assembly debate — and not regard his words as intended for American popular consumption.

In fact, in making the case that Iran’s regime is dangerous — too dangerous to be trusted with nuclear weapons — some of the examples offered by Netanyahu clearly pointed to his intended audience.

“Just look at what the Iranian regime has done up till now, without nuclear weapons… They abetted the killing of American soldiers in Iraq and continue to do so in Afghanistan. Before that, Iranian proxies killed hundreds of American troops in Beirut and in Saudi Arabia. … In the last year, they’ve spread their international terror networks to two dozen countries across five continents — from India and Thailand to Kenya and Bulgaria. They’ve even plotted to blow up a restaurant a few blocks from the White House in order to kill a diplomat.”

A rumor among journalists suggested — though no source could confirm on Thursday — that Netanyahu was asked by the American administration to thank President Obama for his own rhetoric on Iran in his speech Tuesday. It is, after all, campaign season.

If the rumor is true, Netanyahu disappointed, giving no ground to indicate he saw eye to eye with the US president.

“Two days ago, from this podium, President Obama reiterated that the threat of a nuclear-armed Iran cannot be contained,” he began. And while he noted, “I very much appreciate the president’s position as does everyone in my country,” he would only add that “Israel is in discussions with the United States over this issue, and I am confident that we can chart a path forward together.”

In fact, he offered a hinted admonishment, explaining to the American president, “What I have said today will help ensure that this common goal is achieved.”

In simple language, Netanyahu then laid out a beginner’s explanation of his position:

“Basically, any bomb consists of explosive material and a mechanism to ignite it. The simplest example is gunpowder and a fuse. That is, you light the fuse and set off the gunpowder,” he taught.

“In the case of Iran’s plans to build a nuclear weapon, the gunpowder is enriched uranium. The fuse is a nuclear detonator. For Iran, amassing enough enriched uranium is far more difficult than producing the nuclear fuse.”

Since for Iran it “takes many, many years to enrich uranium for a bomb,” and the enrichment must take place “in very big industrial plants,” during the enrichment phase, Iran’s program is “vulnerable.”

However, if Iran completes enrichment and is left with only a detonator to build — a device that can be manufactured “in a small workshop the size of a classroom” in a country “bigger than France, Germany, Italy and Britain combined” — it will be impossible to locate and destroy the program at that point.

“The relevant question is not when Iran will get the bomb. The relevant question is at what stage can we no longer stop Iran from getting the bomb,” Netanyahu concluded.

Netanyahu’s speech was aired, at least in part, on US cable networks. While pundits mocked, millions of Americans heard a simple, clear argument that Iran was quickly reaching a point when its nuclear program would be beyond the reach of Western intervention.

Netanyahu is electioneering. Whether he is actively working to undermine Obama’s Jewish support and bolster Romney’s candidacy is unclear. But there is little doubt he is using the few weeks left till US election day, when a second-term Obama will likely not be as attentive or interested in what he has to say, to drill his point home at every opportunity.

Netanyahu is hoping to convince the American voter that Iran is as immediate a threat as he believes it to be. And through the voter, maybe even Obama himself.