Background: Menachem Begin, father of Benny, was the founder of Likud, built it from scratch, and rose to PM. Benny ran against Netanyahu for the leadership and lost in the early 90s but that's not why he quit. When the Likud pulled out the 1996 election (after the polls showed them losing big-time and Labor celebrated victory in a televised party election night on the basis of exit polls) by opposing Oslo, Netanyahu vacated Hebron because he said they had to honor signed agreements. Begin said that was suicide for the nation and quit the party. He ran as an independent in 1999 and siphoned off enough votes that led to the election of Barak and Labor. Oslo blew up in everyone's face in 2000 when Arafat, having milked all he could, launched a wave of terror. Arafat's goal was to cause such a violent reaction that the Arab nations would come to the Palestinians "rescue" with a huge war. It might have worked but Osama bin Laden wasn't on the same page and attacked America instead of Israel.
The name Begin is still magic and Benny himself will give Netanyahu the backbone not to make foolish concessions even if the Obama crowd demands them, assuming Netanyahu wins the current election.