IfNotNow, which was founded in 2014 during the last Israeli war in the Gaza, now works in 16 cities in the U.S. and says that up to 10,000 people have attended its 350 protests in the last two-and-a-half years. Among their targets have been powerful pro-Israel lobby group AIPAC, and the network of Jewish camps, Camp Ramah. They also protested when President Donald Trump’s former adviser Steve Bannon spoke at the Zionist Organization of America, and organized a demonstration in Washington after the U.S. announced it was moving its embassy to Jerusalem, which infuriated Palestinians.

According to Rabbi Sharon Brous of Los Angeles, a who leads a progressive non-denominational congregation in Los Angeles, IfNotNow is part of a generational shift among Jewish Americans who are alienated by signs of growing illiberalism in Israel.

“There is an enormous number of young American Jews who felt that the only option they had was to buy into the party-line script of the right-wing nationalist support of Israel, or to abandon the Israel conversation altogether,” she said.

Members of the group are more likely to be critical of the Israeli government than their parents and grandparents. A major 2013 Pew survey of American Jews showed that only a quarter of those aged 18 to 29 thought the Israeli government was “making a sincere effort to bring about a peace settlement with the Palestinians.”

U.S. resistance to Israeli policies has existed for years, but it picked up speed after Trump was elected, according to Brous and others NBC News spoke to. The close relationship between Trump and Israeli Prime Minister Netanyahu — a hawkish politician who is in a coalition with Orthodox and ultra-Orthodox parties — has galvanized many, given that a majority of U.S. young people as well as Jews do not support the president. Netanyahu’s links to the U.S. evangelical Christian community has also worried many liberal Jews.

“Some people are asking — how did all this happen?” said Brous.

“How could it be that my sweet Jewish democratic Israel is now detaining journalists at the border and not letting people into the country and interrogating people based on their political views?” she asked, referring to the recent detention and questioning of Jewish journalists and activists as they arrived or left the country.

Among these was Peter Beinart, a prominent liberal American journalist who says he was held and interrogated about his contacts and activities at Ben Gurion Airport in early August. Netanyahu later said the detention was a mistake.

The change in attitudes among American Jews has traditionally not burst into the open because criticizing the state of Israel has long been anathema to community leaders, said Brous.

“There is a tremendous fear about speaking honestly and openly about these Israeli, about Palestinians struggles, about these complexities, because you could lose your job,” she said. “In the name of loving Israel, we have created a firewall to protect Israeli politicians and Israeli policies that I believe are ultimately undermining Israel’s Jewish and democratic nature.”

Another example of what many on the left consider to be an illiberal trend is the list of 20 organizations Israel has banned from entering the country because, the government says, they back the BDS movement, which supports boycotts, divestment, and sanctions on Israel. While it has been fiercely resisted by Israeli officials, it continues to make headway. Last week the pop singer Lana Del Rey became one of many performers to cancel appearances in the country, in her case at a major music festival.