“The ancient will be renovated and the novel will be sanctified,” the theologian Abraham Isaac Kook once said, in what became a moto of religious Zionist thought.

Kook’s embrace of the Zionist movement inspired thousands to join it while remaining observant at a time when most Zionists were secular and most observant Jews were anti-Zionist.

Serving as British Palestine’s chief rabbi until his 1935 death, he helped forged a harmony between secular and observant Zionism that later underpinned the emergence of Israel.

The National Religious Party (NRP) was Labour’s most loyal ally during the decades of its hegemony, repeatedly winning about one-tenth of the electorate. When Likud unseated Labour, the NRP smoothly crossed the aisle and played for the new hegemon the same role it played for its predecessor.

Now, this role is nearly over. The end of the era was announced December 29 last year when Education Minister Naftali Bennett abandoned Jewish Home, a successor to the NRP, and launched a competitor, the New Right.

Jewish Home is now teetering on the brink of the electoral threshold of 3.25 per cent. Even if it surpasses that obstacle it will, at best, be a right-wing government’s fifth wheel.

The days are over when religious Zionism’s politicians engineered and fueled key national moves, like forcing the establishment of the broad government that led Israel during the Six Day War, or spearheading Likud’s settlement drive in the 1980s .

Religious Zionism’s political decline has a happy and less happy side. The happy side is that the historic NRP’s political goals have been realised.

Observant Israelis have established a level of social integration and public prominence that were unthinkable during Israel’s first decades. Back when they were Labour’s allies, observant Israelis never reached high positions in the military, police, secret services, treasury, foreign office and other key agencies. Over the past two generations this has changed radically.

Religious Israelis have served as attorney general, chief of national police, head of the Shin Bet internal security agency, governor of the Bank of Israel, president of the Hebrew University, generals in the IDF, and the list goes on.

Even more importantly, observant Israelis no longer feel, as their grandparents once did, that they need their own politicians in order to secure the religious school system. Most also no longer feel a need to pass any religious legislation.

Back when Rabbi Kook formulated his theology, the Jewish state had yet to be born and its attitude toward Jewish heritage had yet to be shaped. Religious Zionism therefore struggled, for instance, to make the Sabbath the new state’s official day of rest, to make the IDF’s kitchens kosher, to place marriage and divorce in the hands of rabbinical courts, or make cities build synagogues and ritual baths.

Now such goals are anachronistic, because religious Zionism has long ago achieved them.

Mr Bennett’s move reflects this realisation, and attempts to proceed to a new era in which an observant politician heads a non-observant party that salutes tradition, but focuses on secular issues and fields many secular candidates — most notably his close ally, Justice Minister Ayelet Shaked.

But less happily, religious Zionism’s political rump is messianic.

Led by Rafi Peretz, the IDF’s former chief chaplain, the party formed a joint ticket with Jewish Power, a party whose leaders include disciples of Meir Kahane, the racist rabbi who was assassinated in New York in 1990 by an Egyptian-born American.

The joint ticket is designed to attract the extreme-right’s vote, but even with it Jewish Home is expected to win barely half of what it achieved under Bennet.

Whatever happens, the new configuration marks a sharp departure from the legacy of the NRP that was Labour’s longtime ally.

Led by European-educated scholars, that party was dovish — so much so that on the eve of the Six Days War it opposed a preemptive attack, during the war it opposed Jerusalem’s conquest, and after the war it backed the young formula of land for peace.

A half century later, that version of religious Zionism is deep in history’s dustbin along with its territorial moderation, legislative agenda and electoral success.

Amotz Asa-El is a fellow at the Hartman Institute. His new book, The Jewish March of Folly, is an Israeli interpretation of the Jewish people’s political history