Howard Kohr and AIPAC have repeatedly attacked IfNotNow, accusing the group of undermining U.S.-Israel relations and promoting 'divisive' rhetoric. AIPAC has lobbied against IfNotNow's inclusion in Jewish communal spaces and has publicly condemned its protests, such as those targeting Democratic politicians who support Israel. Kohr has described IfNotNow as 'not representative of the Jewish community' and a threat to bipartisan support for Israel.

IfNotNow has publicly opposed David Schenker's policies, particularly his support for the Abraham Accords and U.S. backing of Israel. The group accused Schenker of prioritizing Israeli interests over Palestinian rights and contributing to the marginalization of Palestinian voices in U.S. foreign policy. IfNotNow organized protests and social media campaigns targeting Schenker during his tenure as Assistant Secretary of State.

IfNotNow launched the 'Not Just a Free Trip' campaign, which involved activists 'walking off' Birthright trips in protest of the program's exclusion of Palestinian narratives. In response, Birthright updated its code of conduct in 2019 to allow the expulsion of participants who 'disrupt' trips with political activism.