Israeli Prime Minister Benjamin Netanyahu has shored up his base with a landslide primary victory. But he will need a big win in national elections in March if he hopes to stay in office and gain immunity from prosecution on corruption charges. Netanyahu handily defeated Gideon Saar in a Likud party primary held on Thursday, but turnout was low amid stormy weather, with less than 60,000 votes cast. Netanyahu faces a much greater challenge in March — the third vote in less than a year — after failing to form a government after the last two elections. He will need a 61-seat coalition to secure immunity from prosecution.