The controversy over an invitation to Israel’s prime minister, Benjamin Netanyahu, to address Congress shortly before Israeli elections has polarized the U.S. political scene. Netanyahu has been here before, of course. His transparent support for the Republican candidate for president in 2012, Mitt Romney, generated much resentment in the Democratic Party hierarchy, and certainly in the Obama administration. But this time – together with House Speaker John Boehner – he is a central player in a highly charged national political environment pitting a Republican-controlled Congress against a Democratic president; public and media attention is much greater, and the consequences potentially higher.

How this will play out in terms of U.S. politics and the impact on relations with Israel depends in part upon a more basic question: How do Americans see Bibi Netanyahu in the first place? And how do these attitudes play into a broader, and growing national divide about policy toward Israel? Some of the questions in a November 2014 poll I conducted – fielded by the research company GfK – among a nationally representative panel of 1008 Americans offer some intriguing evidence.

On the surface, Americans seem to view Israel’s prime minister just like they view other Western leaders, more favorably than unfavorably. But probing deeper, my survey reveals that Americans are much more divided about him, particularly across party lines, while younger Americans view him more unfavorably. These divides, coupled with significant and expanding party divides about policy toward Israel, mean that Netanyahu’s planned speech to Congress could force congressional Democrats to become more responsive to their grass roots constituents who are far more critical of Israeli policies – just as potential presidential candidates will be gearing up for primaries.

Let’s start with public attitudes. The poll’s respondents overall expressed a more favorable view of the Israeli prime minister than an unfavorable one; in fact the percentage of those expressing favorable opinions of him is very much on par with those of leaders of friendly Western European countries such as German Chancellor Angela Merkel and British Prime Minister David Cameron – and way ahead of Arab leaders such as Egyptian President Abdel Fatah al-Sissi and Palestinian President Mahmoud Abbas.

But this result betrays a more problematic reality for Netanyahu, especially across party lines and among younger Americans. To begin with, more Americans express unfavorable views of Netanyahu than of Merkel and Cameron. And, probing more deeply, it is obvious that, as on matters of Israel broadly, there is an increasing party divide that cannot be found in American public attitudes toward other Western leaders. Moreover, the favorable views of Netanyahu are shrinking among younger Americans, particularly younger Democrats.

In the poll, I asked respondents to rank each leader on a scale of 0 to 10, where 0 is very unfavorable, 10 is very favorable and 5 is neutral. Not surprisingly about half of Americans in general have neutral opinions on most leaders, in part reflecting limited familiarity. There are a few notorious exceptions such as Russian President Vladimir Putin, who has become a bipartisan target, so that few Americans are neutral about him.

With Netanyahu, the general trend holds: A plurality of Americans, 37 percent, sees him neither favorably nor unfavorably – at least as of November 2014. Thirty-three percent express favorable views while 15 percent express an unfavorable view. His favorable numbers are comparable to those of Merkel and Cameron (30 percent each), but his negatives are higher: 15 percent compared with 6 percent for Cameron and 7 percent for Merkel. The differences are accentuated when results are viewed across party lines, and even more when it comes to those under 45 years old.

Republicans have a much more favorable view of Netanyahu than Democrats. Among Republicans, 49 percent hold favorable views of the Israeli prime minister, while only 9 percent have unfavorable views. In contrast, Democrats are almost evenly divided: 25 percent favorable, 22 percent unfavorable.

To get a sense of perspective on this party divide, it’s useful to compare these numbers with those of Angela Merkel. Among Republicans, 34 percent hold favorable views, 5 percent unfavorable; among Democrats, 31 percent express favorable views, 9 percent unfavorable.

It is also noteworthy that positive views of Netanyahu are much lower for Americans who are under 45, though nationally his negatives remain relatively constant across the different age groups. But among Democrats, age seems a bigger factor. Americans under 45 have a more negative view of Netanyahu than a positive one, with those age 30 to 44 expressing the most negative views: 25 percent unfavorable, 15 percent favorable and 42 percent neutral.

While the American public view of Netanyahu is more positive than negative and is somewhat comparable to other Western leaders, his unfavorable views are also higher than Merkel and Cameron. More centrally, there is a much more pronounced difference in attitudes across party lines. Democrats are almost evenly divided in their attitudes, and those under 45 among them have expressed more negative views than positive ones. This of course is central to the unfolding story of Boehner’s invitation to Netanyahu to deliver a speech in Congress in March, without consulting with (and with the displeasure of) the White House, only a day after President Obama announced that he is prepared to veto any new Iranian sanctions bill. Netanyahu is one of the biggest advocates for new sanctions, and his speech is sure to play into an Iran debate that has become partly partisan.

During a news conference Tuesday, Speaker of the House John Boehner addressed "stumbles" Republican lawmakers have run into so far in 2015 and objections to his invitation of Israeli Prime Minister Benjamin Netanyahu to speak before a joint session of Congress. (AP)

The high profile nature of the looming confrontation is consequential. In the past, most confrontations between the White House and Netanyahu have been over the Israeli-Palestinian issue, which is not a priority for most Americans. Even when they were about Iran, the tension was about a foreign policy issue. And when Netanyahu appeared to favor the Republican candidate over Obama in the election campaigns, that support wasn’t particularly attention-grabbing for the American public, nor particularly significant for the elections’ outcome.

But this time it’s different. It is of course still about the Iran issue, with looming decisions in the coming weeks and months. But it is now as much about polarized U.S. politics. And Bibi has become a central part of the game.

In fact, his visit threatens what has remained a robust congressional bipartisan support for Netanyahu’s policies and requests despite a divided American public. In poll results I released in December and analyzed on the Monkey Cage, it’s clear that Republicans have become far more supportive of Israel than Democrats. In fact, among the young, Democrats are trending away from support for Israel, and diverge markedly on their attitudes on specific issues from the positions of Netanyahu’s government.

So, while congressional Republicans have been much more in harmony with their grass roots constituents on the issue of Israel, congressional Democrats have not. One reason they are able to do this is that for most Democrats, the Israel issue is not especially central in their electoral decisions. Now, it’s different: The Israeli issue has become part and parcel of the partisan tension. If Netanyahu hoped to isolate the president by demonstrating bipartisan support in Congress, on which he has usually counted, the current environment puts congressional Democrats in an untenable position: They are facing a grass-roots constituency that’s very much on the president’s side on this issue, and the issue itself is center stage and deeply about American politics. It’s much harder to fudge, which is why earlier reports that Netanyahu received a “bipartisan” invitation from congressional leaders was quickly challenged by Democratic leaders, including House Minority Leader Nancy Pelosi.

It is of course too early to tell how Congress, Netanyahu and the White House will alter their postures between now and Netanyahu’s scheduled speech on March 3 – or what Netanyahu would exactly say if he were to deliver such a speech. But my guess is that views of him among the American public, especially Democrats, may have become even more polarized. The most important consequence is perhaps that congressional Democrats may now feel they have to look over their shoulders in Democratic primaries on an issue that has not been traditionally front-and-center in U.S. election campaigns.

Shibley Telhami is Anwar Sadat Professor for Peace and Development at the University of Maryland and non-resident senior fellow at the Center for Middle East Policy at the Brookings Institution.