David Ainsman really began to get worried about President Barack Obama’s standing with his fellow Jewish Democrats when a recent dinner with his wife and two other couples — all Obama voters in 2008 — nearly turned into a screaming match. Ainsman, a prominent Democratic lawyer and Pittsburgh Jewish community leader, was trying to explain that Obama had just been offering Israel a bit of “tough love” in his May 19 speech on the Arab Spring. His friends disagreed — to say the least. One said he had the sense that Obama “took the opportunity to throw Israel under the...