Today it is finally happening. Tzipi Livni is announcing her comeback after a very brief break from daily politics and the launching of yet another centrist party. Immediately after the launch, a group of MKs will split from Kadima, the party she founded along with Ariel Sharon and Ehud Olmert in 2005, to join her in the new venture. Middle ground Israelis will then have a bewildering choice between four...