His devotees call him "The Magician," "The Winner" and — the ultimate accolade — melekh yisrael, "King of Israel." Benjamin Netanyahu is Israel's most gifted politician in a generation. He is his country's second-longest-serving prime minister and, if he wins his fifth election on April 9, may beat the record of the country's founding father, David Ben Gurion.

"Bibi," as he is known by all, is important beyond Israel, too, and not only because he speaks in perfect soundbites in both Hebrew and English and stands tall in today's chaotic Middle East. He matters because he embodied the politics of muscular nationalism, chauvinism and the resentment of elites long before such populism became a global force. Netanyahu counts among his friends and allies such nationalists as Donald Trump and Narendra Modi, not to mention European ones from Viktor Orban in Hungary to Matteo Salvini in Italy.

The reign of King Bibi is thus a parable of modern politics: the rise of a talented politician and a long success based on a perplexing mixture of carrying out sound policy and cynically sowing division. As his power is threatened, he has turned to railing more loudly against the free press, the judiciary and shadowy forces. Now Bibi faces his greatest danger, in the form of criminal charges for corruption. In a different age he would have had to resign, and would now be defending himself as an ordinary citizen. But he is intent on remaining in office, and hopes that voters will yet save him from the policemen, prosecutors and judges. Israeli politics is turning into a contest between genuine achievement and demagoguery on one side and the rule of law on the other. All who care about democracy should watch closely.

Little Israel commands attention because it has a big history: biblical romance and technological talent; the slaughter of the Holocaust and military prowess; energetic democracy and the long occupation of land claimed and inhabited by Palestinians. That said, Netanyahu is a big figure in his own right. He is more intelligent and capable than many populists and can claim plenty of successes. By shrinking the bloated state, he has helped Israel's economy flourish, particularly its tech startups. With deft use of diplomacy and the mostly cautious use of military force, he has boosted security without being sucked into disastrous wars. Thanks to that and a shared hostility to Iran, relations with many Arab rulers are better than at any time in Israel's history.

Yet Netanyahu is also worryingly dogmatic. He has paid lip service to peace with Palestinians but has taken no meaningful steps toward it. He has denounced any Western cooperation with Iran, even if it served to limit Iran's nuclear program. In Bibi's pessimistic view, Israel is surrounded by wolves in sheep's clothing and wolves in wolves' clothing. Israel can only manage conflicts, not solve them, he believes, so it must rely on an iron wall and the passage of time.

Such "anti-solutionism" risks storing trouble for the future. It increases the danger of war with Iran, or of its hardliners making a dash for nukes. The more Israel entrenches itself in the West Bank, the more its "temporary" military occupation looks like the permanent subjugation of Palestinians under a separate law, even apartheid. This is made worse by the absence of America's restraining influence. Netanyahu has warmly embraced Trump, who in turn has showered him with gifts, most recently his endorsement of Israel's annexation of the Golan Heights. Might Trump also back Israel's annexation of bits of the West Bank, so denying Palestinians the hope of statehood? In the long run, Bibi's overt alignment with America's Republicans and the evangelical right endangers the bipartisan pro-Israeli consensus in Washington that is the foundation of Israel's security.

But the greatest threat from Bibi's reign has been at home. He has kept power not just on the strength of his record but also by seeking political advantage at the cost of eroding Israel's democratic norms. In claiming that no peace with Palestinians is possible (or desirable), members of his right-wing coalition outbid each other to pass measures asserting Jewish supremacy. Netanyahu pushed for an electoral pact with the hitherto untouchable far-right Jewish Power group, which wants to annex all the occupied territories and "encourage" Arabs, including Israeli citizens, to leave. He has played us-and-them politics for so long that he has exacerbated the country's many schisms — between Jews and Arabs, diaspora Jews and Israelis, western Ashkenazi and eastern Mizrahi Jews, and secular and religious ones. By casting himself as uniquely able to protect Israel against its enemies, he often treats those who say otherwise as wimps or traitors.

Netanyahu and his friends denounce as backstabbers any Jews who stand in their way. The free press peddles fake news. Political opponents, even the generals who pack the new Blue and White opposition party, are in cahoots with the Arabs. Bibi has flirted with the conspiracy theory beloved of anti-Semites that George Soros, a Jewish billionaire, is plotting to undermine nationalist governments around the world.

The corruption charges against him, says Netanyahu, amount to a "blood libel" — a vile medieval canard that accused Jews of mixing the blood of murdered Christian children in their Passover bread. Yet the police chief who investigated the charges, and the attorney general who ordered his indictment, were both hand-picked by Netanyahu. His allies want a law that would grant a prime minister immunity from prosecution.

Israel is an outlier among Western democracies. It was born as the state of the Jews; Zionism and Palestinian nationalism claim the same land. Israel must contend with a genuine "other" and existential threats, not the bogeymen invented by populists elsewhere. The left, in disarray in many countries, suffered a body-blow in Israel because its attempt to negotiate a land-for-peace deal with Palestinians collapsed into bloodshed.

Yet precisely because of these pressures, Israel offers an important test of the resilience of democracy. On April 9 Israeli voters face a fateful choice. Re-elect Netanyahu and reward him for subverting the independence of Israel's institutions. Or turf him out in the hope of rebuilding trust in democracy — and aspiring to be "a light unto the nations."

Copyright 2013 The Economist Newspaper Limited, London. All Rights Reserved. Reprinted with permission.