Short Course (Sovietologists should enjoy the title) in how Stalin organized the USSR. First he gained power as the chief bureaucrat within the Party--General Secretary). As they built an industrial state out of an agrarian/hunter gatherer empire, plants to produce parts,subassemblies were spread all over as patronage for the local CP bosses (typically the ethnic president of the "national republics" was a figurehead while his first deputy was a Russian--Stalin loyalist). All of this is back ground to the US DOD vendors spreading parts sub suppliers such that one major ICBM literally represented jobs in nearly evey House district--thus "forcing" support despite the utter non utility of the weapon system.
So, whether a pseudo-Marxist police state, or a pseudo democratic capitalist republic, the processes are very similar.
BART was "sold" to the DOD vendors at a point where aerospace spending was down and they needed contracts. It all worked well (except for the tax payers who were seriously ripped off) with typical fraudulent low ball bids which turned into major change orders, delays, out of spec crappy products. IBM admitted they were using BART as a test bed for their entry to the magstrip ticket/turnstile business thus charging less than it cost to do the work. So we got a few new rapid transit systems which kind of work except in high heat (the switching hardware at Daly City), snow in WMATA's case (apparently they never asked NYC how to run subway cars in the open after a blizzard), and then we got the Light Rail rebranding of streetcars starting with San Diego giving the Feds the finger by buying off the shelf German cars.
That didn't last long, all of the systems now buy "specified domestic content" and often a temporary jobs program within the transit district or nearby counties in order to get the FTA check writers going. So yes, patronage, it seems to be how it works be it GOP perps from your favorite SF based co. revolving through the Fed Gov, or the evolution of CP bosses into first The New Class (a critiquie from Joseph Tito's best friend from WWII partisan days published in the US with CIA money) and now the "oligarchs who simply seized at a penny on the ruble the former state industries/factories, and now stash their profits in Deutsche Bank, London and NYC real estate far from the sainted workers they have fleeced.