Republicans are seeking to drive a wedge into an issue that’s already emerging as a highly sensitive one in the Democratic platform: Israel. The latest salvo will come from the Republican Jewish Coalition this week, as the group—which is home to some of the biggest donors in GOP politics—launches an online advertising campaign attacking members of the Democratic National Committee’s platform drafting committee. The RJC plan, first shared with POLITICO, comes as Democrats are already grappling with the possibility that the Israeli-Palestinian conflict will emerge as a major flashpoint at their national convention next month, given the sharp disagreements some...