His jet is a Boeing 757-200 that does not have the range to fly to Israel directly from anywhere in the US. Also, as it is an older twin engine jet, it is not allowed to fly anywhere that is more than 120 minutes from a landing field that can take it under the ETOPS regulation.
There is additionally the small matter of currently being under indictment and out on bail while a trial occurs and having the jetliner publicly head overseas would be an image his lawyers would scream at.
From Wiki
Its range with full payload is 3,850 nautical miles (7,130 km; 4,430 mi)