Caretaker Prime Minister Yair Lapid (left) faces a challenge from the returning Benjamin Netanyahu (right).
Jerusalem CNN  — 

Stop us if you’re heard this one before: On Tuesday, Israelis are going to the polls to elect a new Knesset, or parliament. It’s the fifth time in less than four years that voters are casting ballots. Holding elections that often is bound to prompt some questions. Here are some answers.

Why does Israel have elections so often?

Israel has a parliamentary system made up of several parties – none of which have ever received enough votes on their own to secure a majority of seats in parliament. That means parties must team up to form coalitions and reach the 61 seats needed to form a ruling government. Those coalitions can also be shaky – lose one party’s support, or sometimes even one member of parliament, and you’ve lost the majority.

The other factor is Benjamin Netanyahu. He served as prime minister for longer than anyone else in Israeli history, is in the midst of a corruption trial, and overall is a polarizing figure. Some top politicians on the center-right, who agree with him ideologically, refuse to work with him for personal or political reasons.

That made it difficult for him to build lasting governing majorities following the previous four elections, and last year, his opponents managed to cobble together a never-before-seen coalition of parties from across the political spectrum to keep him out of power. But that coalition only held together for about a year and a quarter before its leaders, Yair Lapid and Naftali Bennett, pulled the plug and called for new elections.

Who are the main contenders this time around?

Netanyahu’s center-right Likud party will almost certainly be the largest party in the Knesset after Tuesday’s vote, if the polls are correct. They’ll probably win about 30 seats, a quarter of the total, a compilation of polls by Haaretz, for example, suggests.

Current Prime Minister Yair Lapid will be hoping his centrist Yesh Atid party will come in a strong second place.

The man he partnered with to assemble the last government, Naftali Bennett, is not running this time around; his party has splintered and faces a potential electoral wipeout.

Defense Minister Benny Gantz is aiming for a strong showing at the head of a new party called National Unity, a successor to his Blue and White party which now includes former Bennett ally Gideon Saar and former Israel Defense Forces chief of staff Gadi Eisenkot, making his political debut.

A far-right coalition called the Religious Zionist Party, headed by Bezalel Smotrich and Itamar Ben Gvir, could be the largest extreme right-wing group ever seated in the Knesset.

On the other hand, the once-mighty Labor Party and its predecessors, which governed Israel essentially as a one-party state for its first 30 years under David Ben-Gurion and his successors, is a shadow of its former self, and is projected to win only a handful of seats.

How does the election work?

Israel is a parliamentary democracy, where people vote for the party they support. Each party that gets at least 3.25% of the popular vote gets a certain number of seats in the Knesset based on the percentage of the total number of votes it won.

The 3.25% threshold is intended to keep very small parties out of the Knesset, an attempt to make it easier to build governing coalitions.

Israel has experimented in the past with electing the prime minister directly, separate from the Knesset, the way the US elects the president and Congress separately. It proved unwieldy and the country went back to standard parliamentary elections.

What’s expected to happen?

The final polls suggest that Netanyahu’s party and its potential allies are hovering right around the knife edge number of 60 seats and the drama of election night will be whether the former PM scrapes above it.

If his bloc clearly wins a majority, his path to building a government is clear and he will return to power.

If the pro-Netanyahu bloc falls below 61 seats, things are more complicated. Netanyahu would still probably have the first chance to form a government if his Likud party is the biggest in the Knesset, which could result in days or weeks of negotiations that go nowhere.

Netanyahu speaks to supporters in a modified truck during a campaign event this month.

If he fails, President Isaac Herzog can then decide to give the mandate to current Acting Prime Minister Lapid, or to another lawmaker whom Herzog calculates may have the best chance to form a government.

That could mean no one can build a majority government, raising the possibility of … more elections. While party negotiations are taking place and until a new government is formed, Lapid remains in place as caretaker prime minister.

What are the key issues for Israeli voters?

Israelis are concerned about many of the same issues that people around the world are – the cost of living in particular.

They are also always focused on security. In the region, Iran’s nuclear ambitions and support of militant groups are always a worry, and more locally, violence is high this year between Israelis and Palestinians.

Some constituencies have their own specific concerns, such as the ultra-Orthodox, who want state support for their institutions and exemptions from army service; and religious Zionists, who want backing for West Bank settlements.

But overwhelmingly, Israeli elections these days are about one issue and one man: Benjamin Netanyahu.

Correction: This article has been updated to remove an incorrect reference to which Arab party supported Yair Lapid's government, and to better explain how Lapid could get the mandate to form a new one.