Ben Smith has some strong reporting to show that the concerns about President Obama's policy toward Israel among American Jews -- specifically liberal, non-single-issue pro-Israel Democrats --  are real:

One said he had the sense that Obama “took the opportunity to throw Israel under the bus.” Another, who swore he wasn’t getting his information from the mutually despised Fox News, admitted he’d lost faith in the president.
If several dozen interviews with POLITICO are any indication, a similar conversation is taking place in Jewish communities across the country. Obama’s speech last month seems to have crystallized the doubts many pro-Israel Democrats had about Obama in 2008 in a way that could, on the margins, cost the president votes and money in 2012 and will not be easy to repair.
“It’s less something specific than that these incidents keep on coming,” said Ainsman.

Smith also quotes DNC chairman Debbie Wasserman Schultz, who provides a quote supporting Obama while signalling that the existence of voter concern is real.

On the other hand, it's worth keeping in mind that some sequencing is going to alter the dynamic. In September, the Palestinian Authority is going to unilaterally push for statehood. The United States plans to oppose that. So, starting in a few months, Obama's administration will be in the position of standing with Israel and against most of the world. That should significantly alter the perception that Obama is constantly needling Israel.

Now, the reality is that the two aspects of Obama's Middle East policy are complementary. Obama is pushing the Israeli government to demonstrate its reasonableness toward negotiation so as to establish a negotiated peace as an alternative to unilateral Palestinian statehood. (That push also helps established American credibility to support Israel in the U.N.) Benjamin Netanyahu has stupidly refused to concede a reasonable negotiating posture, and will thus go into the vital fall showdown unnecessarily isolated.

But, in any case, the sequencing of the Middle East diplomacy is going to work pretty well for Obama's domestic political needs.