It's a form of money laundering. Create a local project that you can inflate all the invoices on. The goal is to shift public "taxpayer" money into the hands of private operators, preferably your mates, and some of that money will "somehow" end up in your hands. Even better if you hire a company with an offshore subsidiary as it's much harder to track monetary flow and can end up in your Caymans bank account.
If you want a fun way to look at pretty much everything in a different light, I highly recommend watching the Ozark tv series.
Both major parties have been doing it, well, forever really.