One obvious aspect of this is how everybody on both sides have long histories with everybody else. Blumenthal, author of Goliath, a book about how Israel isn't actually the plucky little David fighting the giant Palestinian juggernaut, is the son of Clinton consigliere Sidney Blumenthal. (Heck, I can vaguely recall being denounced by young Blumenthal as an anti-Semite for, of all things, an article of mine celebrating the Jewish contribution to the Christmas song genre.)
James Kirchik, winner of the 2006 National Lesbian and Gay Journalists Association Excellence in Student Journalism award, is one of the former bright young things of long-time New Republic supremo Marty Peretz, a lineage of one-time ambitious young fellows that include Andrew Sullivan and the teenage Al Gore.
There are lots of interesting linkages in Blumenthal's article, such as Victoria Nuland.
Getting totally off track, I've always been impressed by how Peretz overcame his inclinations and went forth and multiplied to perpetuate the race, so I looked up what his two kids are doing. It turns out that Jesse and Evgenia Peretz are that rarest of contemporary movie-making duos, the Sibling Act. (Wachowskis not included in this count). There are lots of creative Brother Acts (Coens, Farrellys, DuPlasses, etc.), but the recent movie Our Idiot Brother starring Paul Rudd was directed by Jesse Peretz with a screenplay by his sister Evgenia Peretz and her husband.