Prime Minister Benjamin Netanyahu has been compared to an evergreen tree: He is politically strong and impressive, but nothing can grow under him.However, nothing lasts forever, and a number of challengers are poised to take on the mantle of future leaders of the Right in a post-Netanyahu era, if that ever arrives.Two of them sit in Netanyahu’s coalition and were, incidentally both former Netanyahu aides: Bayit Yehudi, led by Naftali Bennett, and Yisrael Beytenu, headed by Avigdor Liberman, both former Likudniks.Both see themselves as future leaders of the country, and heads of a future right-wing alignment that could challenge Netanyahu.Could Bennett and Liberman also return to Likud? That will depend on political circumstances.For instance, Netanyahu could work out a deal with Bennett on a joint Likud-Bayit Yehudi list ahead of the next election, in order to ensure that Netanyahu will head the largest party. That could be a first step toward Bennett returning to the Likud and, perhaps, eventually taking it over. While that experience did not work out well when Likud and Yisrael Beytenu ran together in 2013, in politics, necessity is the mother of invention. Sa’ar could form another party ahead of the next election, perhaps with Finance Minister Moshe Kahlon and former defense minister Moshe Ya’alon. Polls show he could do well, attracting support from the Right, Center, and even the Left, despite his firm opposition to a Palestinian state. However, Sa’ar stresses that he is a proud Likudnik, and he is very popular among Likud activists. He has denied recent headlines that he has already decided to end his political time-out, come back and run in the next Likud primary.The most likely scenario is that he will stay on the sidelines until Netanyahu leaves and clears the way for him.