"In the bigger electoral picture, according to the polls, Ayalon poses a great threat to Likud leader Netanyahu. This was largely born out by yesterday’s primary first round results. Barak’s main support came from vote contractors and the support he received amongst the old guard of the party machine, as well as amongst the Arab and Druze communities – all of which are largely irrelevant to the Labour Party when it comes to general elections. Ayalon, by contrast, polled well where the election was genuine and genuinely competitive and where Labour needs to grow its strength in the general elections, notably in the large cities (Ayalon won Tel Aviv, Jerusalem, and Haifa)."
Of course this analysis presumes Labor primary voters are an indicator for the general Israeli public, which I question.