Once Israel’s elections end, the horse trading begins. A prime minister may offer any constellation of incentives, from ministerial posts to program funding and policy changes. Netanyahu has long been respected for his ability to coax unlikely allies and to maintain a fluid rotation of parties within his government.

He surprised many when, in the midst of election season, he announced a merger of his right-wing Likud Party with the right-wing Israel Beiteinu to form a new movement called "Likud-Beiteinu."

"Netanyahu will take a bit from the left and a bit from the right," said Moshe Harmoni, a long-standing Likud activist, who said he’d backed the party for nearly three decades. "All that matters to him is that he stays prime minister."

His last coalition began with Israel Beiteinu, the religious Orthodox Shas party, left-leaning Labor and the ultra-nationalist Jewish Home. It was suddenly strengthened when he shocked political pundits last May by announcing that his longtime foe and opposition leader, Shaul Mofaz, had agreed to form a unity government and join the coalition.

"The coalition has nothing to do with who you have the most in common with or can agree with," said an aide to Netanyahu, who spoke only on the condition of anonymity because he wasn’t authorized to discuss coalition dealings with the press. "A coalition is formed with whomever you think you will keep you in office the longest and with the fewest headaches.”

Likud-Beiteinu’s surprisingly weak showing in the polls and the rise of centrist parties such as Yesh Atid might force Netanyahu to abandon some of his stalwarts, such as Shas.

On Tuesday night, frequent calls of "don’t let Shas in" and "dump Shas" interrupted Netanyahu’s victory speech at Likud headquarters. Likud voters expressed frustration with Netanyahu for repeatedly caving to the Shas party during his time in office.

"They held him back from everything and stole the government coffers for the Orthodox," said Chava Mazor, a 32-year-old Likud voter. "I really want Netanyahu to be prime minister, but I really hope he picks better friends for his coalition."