Here's one source, there are others. I actually heard about this 10 or 15 years ago and this is a recent article about it:

Adding so much new technology serves a political purpose unrelated to any combat function. Each gadget added to a weapon needs to be built somewhere and so becomes a new subcontract to the whole endeavor. Spreading these subcontracts around the country guarantees support in Congress. As more congressional districts have a piece of the acquisition action, more members of Congress will have a vested political interest in seeing the program continue. The F-35 program takes this practice, sometimes called political engineering, to an extreme. Lockheed Martin’s F-35 website includes a page dedicated to the program’s economic impact: An interactive map shows suppliers in 47 states.

https://www.pogo.org/analysis/has-the-pentagon-learned-from-the-f-35-debacle

Also: https://infogram.com/f-35s-1hke6098w1v565r