But his various corruption scandals have created some voter fatigue, and in recent days he's vowed to annex Jewish West Bank settlements if re-elected -- a prospect that could doom the already slim hopes of establishing a Palestinian state alongside Israel, which Netanyahu has previously wavered on.
Netanyahu faces a stiff challenge from retired military chief Benny Gantz, whose Blue and White party has inched ahead of Netanyahu's Likud in polls. Netanyahu still appears to have the best chance of forming a coalition, though, with a smattering of small nationalist parties backing him.
Netanyahu and Gantz have ruled out sitting together in government, so the next prime minister will likely come down to how many supporters each candidate can recruit.
Israel's president, Reuven Rivlin, could play an important role. Though largely a ceremonial post, the president is responsible for choosing the candidate with the best chance of building a stable coalition government as prime minister.
In the campaign's final days, Netanyahu has veered to the right and embarked on a media blitz in which he portrays himself as the underdog and frantically warns that "the right-wing government is in danger."
Arab turnout will be a major issue this time as well. Netanyahu's campaign against Arab politicians, together with the new alliance with anti-Arab extremists and the passage of last year's contentious nation-state law, which enshrined Israel as the homeland of the Jewish people alone, have deepened calls for a ballot boycott in Arab communities.
But some hope these blows will have the opposite effect, fueling enough frustration to drive up the Arab participation rate, which is typically lower than that of Israeli Jews. A big Arab turnout could push smaller right-wing parties into the margins and even threaten Netanyahu's long rule.
The Palestinian issue has been largely sidelined in the election campaign that has been long on scandal and short on substance. But in a reminder, the military says it imposed a 24-hour closure on the West Bank and Gaza throughout election day, based on its security assessments.
Even if he is re-elected, Netanyahu could have a difficult time governing. Some of his allies have indicated they will no longer back him if formal charges are filed.
Israel's attorney general has recommended indicting him on bribery and breach of trust charges in three separate cases. Rivals have also begun to question a deal in which Netanyahu reportedly earned $4 million on a German submarine sale to Egypt by owning shares in one of the German manufacturer's suppliers.
Netanyahu denies any wrongdoing and claims the accusations are part of a liberal media's orchestrated witch hunt against him.
Netanyahu has generated much of his popularity from projecting a tough image in the face of Iran's rising power and for keeping Israel safe and prosperous in a hostile region.
But in Gantz he has encountered the rare opponent who can match his security credentials. Along with two other former military chiefs on his ticket, Gantz has attacked Netanyahu for failing to halt rocket fire from the Hamas-ruled Gaza Strip. The telegenic Gantz, who has been vague on key policy fronts, has presented himself as a clean, scandal-free alternative to Netanyahu