Reform Rabbi Ammiel Hirsch, co author of One People, Two Worlds: A Reform Rabbi and an Orthodox Rabbi Explore the Issues That Divide Them, recently told Peter Beinart why he's wrong on all the important accounts which have created Beinart's recent (in)famy. Hirsch is Reform, lives and works in New York, and so far as I can see is as representative of a segment of American Jewry as anyone else - except for the fact that he served in the IDF.
The transcript of his talk needs to be read in its entirety, which can be found over here (h/t Marek).
Sadly, we aren't told how Beinart responded. I expect Ammiel's words effected him like water off the back of a duck, with the added value that being a duck is proving very lucrative for Beinart.