Israel has become a deeply partisan issue for ordinary Americans as well as for politicians in Washington, a shift that may represent a watershed moment in foreign policy and carry implications for domestic politics after decades of general bipartisan consensus.

Republicans by a ratio of more than 2-to-1 say the U.S. should support Israel even when its stances diverge with American interests, a new Bloomberg Politics poll finds. Democrats, by roughly the same ratio, say the opposite is true and that the U.S. must pursue its own interests over Israel's. 

Further illustrating how sharply partisan the debate has become, Republicans say they feel more sympathetic to Israeli Prime Minister Benjamin Netanyahu than to their own president, 67 percent to 16 percent, while Democrats are more sympathetic to President Barack Obama than to Israel's prime minister, 76 percent to 9 percent.

The survey also highlights how differently the nuclear negotiations with Iran are seen between Republicans and Democrats.

Democrats, by a nearly 3-to-1 ratio, said they were more optimistic than pessimistic that a tentative deal with Iran announced this month will contain Iran's ability to get nuclear weapons and thus make the world safer.

By a 2-to-1 margin, Republicans were more pessimistic than optimistic about the impacts of a deal. Majorities of Americans in both parties say any deal Obama makes with Iran should be subject to congressional approval, and that Iran is an unreliable negotiating partner because it is a religious theocracy. 

 
 

The survey follows months of concerns about nuclear negotiations with Iran that have served to intensify an alliance between Netanyahu and congressional Republicans against the policies of Obama. Netanyahu has said that a nuclear Iran poses an existential threat to Israel and has opposed the nuclear talks in their current form. The deal aims to lock down nuclear concessions and intensive inspections of Iran's program in exchange for limited enrichment and an easing of sanctions.

The national poll is consonant with the strongly pro-Israel positioning by most of the Republicans jumping into the 2016 presidential nominating contest. The prospective nuclear deal with Iran, a priority of the Obama administration, has knit the issues closely together.

 
 

These findings come as the percentage of Americans who say they approve of Obama's overall handling of foreign policy has inched up from 37 percent in a December poll to 42 percent today.

“Israel is an emotionally charged issue, period,” said J. Ann Selzer, president of West Des Moines, Iowa-based Selzer & Co., which conducted the poll. “It’s affecting a broader audience than the Jewish vote.”

On the question of whether to support Israel's interests even when they diverge from America's, independents are closely divided, 48 percent to 44 percent, a bare plurality in favor of supporting Israel because of its importance as an ally and the only democracy in the region.1Republicans say yes by 67 percent to 30 percent, while 64 percent of Democrats say the U.S. must pursue its own interests over Israel's. 

One likely Republican presidential candidate, Wisconsin Governor Scott Walker, is visiting Israel next month and told the Associated Press that he “absolutely” plans to meet with Netanyahu. Texas Senator Ted Cruz embraced Israel in his presidential announcement, calling on students at a Christian college to “imagine a president who stands unapologetically with the nation of Israel.”

Taken in concert with the March 9 letter written by congressional Republicans to Islamic leaders in Iran questioning the force of any deal they might cut with Obama, Selzer said, the poll findings also suggest a further erosion of the old mantra that politics stops at the water's edge.

“Now it's fair game in a way it wasn't before,” Selzer said.

 
 

Religion appears to play an important role in shaping the numbers. Born-again Christians are more likely than overall poll respondents, 58 percent to 35 percent, to back Israel regardless of U.S. interests. Americans with no religious affiliation were the least likely to feel this way, at 26 percent.2 Ideological identification also has a strong connection: 62 percent of self-identified conservatives say supporting Israel is key, while that drops to 35 percent among moderates.3

Robert Veenstra, 31, a Catholic Republican and self-described conservative from North Port, Florida, who participated in the poll, said he doesn't yet have a strong preference among Republican presidential hopefuls—but that support of Israel is crucial. “I believe Israel needs the support,” he said. “As far back as you go in recorded history they've always been a people who others have tried to oppress.” At the same time, he offered a caveat to his own view that the U.S. should support Israel's interests even when they diverge, saying he's comfortable taking that stance because Israel isn't asking for anything that truly imperils the U.S.

“While I care about the relationships we have with other countries, and other people's suffering, at the end of the day my country is most important to me,” he said.

For many Democrats, even Jewish ones, the issue doesn't have the same purchase. Jeremy Fischer, 26, a Jewish Democrat from New York, said while he's inclined to back his party's nominee for president, he'd be open to supporting a moderate Republican, such as New Jersey Governor Chris Christie, but that Israel and Iran are not likely to be the issues on which that support will hinge. Meanwhile, the alliance between Netanyahu and U.S. House Speaker John Boehner is a turnoff to Fischer, who said, “I'm just not a fan of Boehner in general and I kind of tend to think Netanyahu is a blowhard.”

When it comes to Jewish voters specifically, Fischer said, “my guess is people closer to my age would skew one way and people closer to my parents' age or grandparents would skew another. The closer you are in age to the Holocaust the more likely you are to believe Israel is right all the time.” The biggest vulnerability for Democrats when it comes to losing Jewish votes would be if the Republican Party chose a moderate nominee, he said, but, “I'm not optimistic about that.”

The survey of 1,008 adults, conducted April 6-8, has a margin of error of plus or minus 3.1 percentage points. The margin of error for subgroups is higher, including +/- 5.6 percentage points for Democrats, +/- 6 percentage points for Republicans, and +/- 5 percentage points for independents. Read the full poll questions and methodology here.