SOMETIMES even the best-hatched plans go awry. A year ago Israel’s foreign minister, Avigdor Lieberman, pushed for a law to raise the threshold parties needed to enter the Knesset, from 2% to 3.25%. Mr Lieberman has long campaigned to reduce the presence of Arabs in Israel’s parliament and, like others on the right, hoped the move would sideline if not eliminate three small Arab parties each of which holds three or four seats. The ploy had the opposite effect. Fearing political purgatory in Israel’s March 17th elections, the three parties pulled off the impossible and joined forces to create a single bloc, the Joint List. It could become the fourth-largest party and determine Israel’s next government.

Meanwhile Mr Lieberman’s party, Yisrael Beiteinu (“Israel Our Home”), faces oblivion. Buffeted by a series of corruption scandals and its leader’s confusing flip-flops, it is fast slumping towards the minimal threshold. Many savour his comeuppance. “We won’t shed a tear,” chuckles Mtanes Shihadeh, an Arab pollster.

Arabs form about 20% of Israel’s 8m population. Mainstream parties, both left and right, routinely field the odd Arab candidate and Arabic is often heard in the Knesset’s corridors, where it survives as an official language. But there are far fewer Arabs in the Knesset than their demographic weight would suggest. Most Arabs in East Jerusalem, which Israel occupied in 1967, cannot vote. And many others elsewhere choose not to. In the 2013 election 56% of Arabs voted against almost 70% of Jews.

That might now change. The new amalgam of Hadash, a communist party championing feminism and Jewish-Arab coexistence; Raam-Ta’al, a conservative faction led by Islamists; and Balad, a party of staunch Arab nationalists, makes an odd cocktail. Arab voters had long tired of their petty infighting. Such is the buzz inspired by the single bloc that some pollsters predict it may boost the Arab turnout to 70%, increasing the number of seats held by Arab parties by anything between one and four seats. “We might see a radical change,” reckons Mr Shihadeh.

Some nostalgic leftists dream of electing a government like Yitzhak Rabin’s in the early 1990s, when Arab parties provided enough support from the backbenches to secure an historic Israeli-Palestinian peace agreement. But such an alliance seems hard to repeat. Yitzhak Herzog’s Labour Party, now part of the expanded Zionist Union, would probably rather align with right-wingers than stake its legitimacy among Jews by allying itself with an untested Arab bloc. Even that wish looks unlikely. For now the Likud party of the prime minister, Binyamin Netanyahu, maintains its narrow lead in the polls.