The Republican Jewish Coalition reports a seismic shift in Jewish voters party affiliation:

In an analysis released today (Thursday), the Pew Research Center noted:

Even Jewish voters, who have traditionally been and remain one of the strongest Democratic constituencies, have moved noticeably in the Republican direction; Jewish voters favored the Democrats by a 52-point margin in 2008 but now prefer the Democratic Party by a significantly smaller 36-point margin.

SOURCE:  http://www.pewforum.org/Politics-and-Elections/Trends-in-Party-Identification-of-Religious-Groups.aspx  

Republicans have also seen gains among Jewish voters, who have long been strong supporters of the Democratic Party. In 2008, 72% of Jews identified themselves as Democrats or said they leaned toward the Democratic Party, and Democrats held a 52-point advantage among this group. In 2011, the Democratic advantage among Jews has shrunk to 36 points, with 29% of the Jewish population aligning with the GOP. While the majority of Jews are still Democrats or lean toward the Democratic Party, Democrats' dominance among this group has weakened since the last presidential election. In fact, Jews are the only religious group analyzed in which the percentage who identify themselves as Republican (as opposed to leaning toward the GOP) has risen significantly. [Emphasis added.]

SOURCE: http://www.pewforum.org/Politics-and-Elections/Trends-in-Party-Identification-of-Religious-Groups-affiliation.aspx 

Reporter Josh Nathan-Kazis in the Jewish Daily Forward quotes Pew researchers on what distinguishes the data on Jewish voters in their analysis:

"The increase among Jews is greater than in the general public, and greater than the increase in... other religious groups," said Alan Cooperman, associate director for research at Pew...

"For most religious groups and for the public as a whole, the trend toward the GOP has come from people who are increasingly likely to say they lean toward the Republican party," said Greg Smith, a senior researcher at Pew. "Jewish voters are really the exception.That's the one religious group we've analyzed where the shift toward the GOP is not among leaners, but rather among actual Republican identifiers."

SOURCE: http://www.forward.com/articles/150747/ 

Ed Lasky adds:

I suspect there are more reasons than the treatment of Israel that are causing the  shift. I wrote about this happening in August, 2010 You can only rail against Wall Street, bankers, doctors, and above-average income earners for so long before people take the blinders off....