Close to four years ago, Avigdor Lieberman became Israel’s foreign minister, and with a few laudable exceptions, the American Jewish establishment shrugged. “There is nothing in his speeches that indicates someone who would threaten the shared values that we have,” insisted the Anti-Defamation League’s Abraham Foxman. “There [is] a lot of exaggeration and hype about who he is…It’s really a much more nuanced picture than people have jumped on here in creating a straw man,” added Malcolm Hoenlein of the Conference of Presidents of Major American Jewish Organizations. “Different can be scary,” explained the Israel Project’s Jennifer Laszlo Mizrahi. “There were people who thought Barack Hussein Obama was scary because of his middle name.”

Yes, different can be scary. In his youth, Lieberman was briefly a member of Meir Kahane’s Kach Party, which proposed stripping non-Jews of their citizenship and criminalizing sex and marriage between gentiles and Jews. And Lieberman has spent his entire career demonizing, and trying to disenfranchise, Israel’s Palestinian citizens (those who live within the green line). He’s demanded that they pledge loyalty to Israel as a Jewish state and lose citizenship if they refuse. He’s pushed for Palestinian Israeli parties that opposed the Gaza war to be disqualified from running in Israel’s elections. In 2009, he ran under the chilling slogan, “only Lieberman understands Arabic.” Palestinian reporters have been barred from covering rallies held by his party, Yisrael Beiteinu. And outside a party rally in 2009, a group of young Yisrael Beiteinu supporters were seen yelling “death to Arabs” at passing cars.

Who knows what might have happened had American Jewish leaders told Benjamin Netanyahu that they considered Lieberman and his party beyond the pale, had they mustered the same outrage they routinely muster when Israel’s government threatens the rights of non-Orthodox Jews. We can’t know. What we do know is that after almost four years of American Jewish leaders rationalizing and looking the other way, Lieberman’s Yisrael Beiteinu and Netanyahu’s Likud have now merged.

For the Israeli right, this represents a historic shift. Historically, Likud has been a liberal party committed to “greater Israel.” In other words, it’s been schizophrenic. There’s always been a deep contradiction between Likud’s support for Israeli control of the West Bank, where only Jews enjoy citizenship, and its commitment to citizenship and democratic protections for those Palestinians who live inside the green line. Still, many of the older generation of Likud leaders—from Benny Begin to Dan Meridor to Reuven Rivlin—genuinely view themselves as liberals, and that self-perception has led them to resist efforts to infringe upon democratic norms within Israel proper, sometimes more strongly than has the Israeli center-left.

The Likud-Yisrael Beiteinu merger heralds the death of that liberal Likudnik tradition. As Haaretz editor Aluf Benn noted yesterday, Likud will now become “a radical right-wing party, aggressive and xenophobic,” a party that “sees the Arab community as a domestic enemy.” In a second Netanyahu term, Benn predicts, Meridor, Begin and Rivlin—if they even remain in government—will no longer be able to block Lieberman’s efforts to strip Israel’s Palestinian citizens of basic rights. And the chances of Israel’s government successfully pushing through legislation to cripple non-government organizations that criticize Israeli policy will also dramatically rise. “The checks and balances,” Benn warns,“have been crushed to bits.”

All this, of course, will only empower those on the anti-Israel left who insist that there is no meaningful distinction between Israel east and west of the green line, who declare that Israeli democracy is a sham. Israel will become more of a pariah, and American Jewish leaders will reach new heights of fury as they denounce the world’s hostility to the Jewish state. And perhaps it will occur to the more thoughtful among them that the best way to prevent Israel’s demonization might have been to fight Lieberman’s ascension in the first place. But by then it will be too late.