Pro-Israel megadonors like Sheldon Adelson and others would likely sit out the general election if Donald Trump is the Republican Party’s nominee, former Cruz spokesperson, Rick Tyler suggested on Tuesday.

In an interview with Politico’s Glenn Thrush on his podcast “Off Message,” Tyler said “it’s certainly possible” that a guy like Adelson or Paul Singer – whom any Republican nominee would need to beat Hillary – would remain neutral in the race for president if Trump is the nominee given his recent comments on Israel. “I mean, because, on the one hand, you have Donald Trump who just doesn’t seem to understand the Middle East and its problems and how to move forward with it, and then, on the other hand, you have Hillary Clinton who was for many years the Secretary of State when the whole Middle East blew up,” Tyler explained.

Tyler, who served as Cruz’s communications director until he got fired for circulating an inaccurate transcript of a statement Marco Rubio said in a recorded video, argued that Trump would be vulnerable because he would come under immense scrutiny, but also because “Hillary Clinton will hammer him and expose him for what he is.”

On Wednesday, over fifty Republican foreign policy experts signed a letter saying Trump would be a disaster for U.S. foreign policy and vowed never to support him.

“1972 was the first time I was old enough to vote for president, and I did not vote. Couldn’t vote for McGovern for foreign policy reasons, nor for Nixon because of Watergate,” Elliott Abrams was quoted as saying. “I may be in the same boat in 2016, unable to vote for Trump or Clinton.”