Trump's decision to force TransCanada to use USA pipe and materials is a very foolish one.  It's a safe bet that if he stays firm with this decision, it will increase the overall price of the pipeline by about 20%; US steel companies will undoubtedly increase prices when they know their President is eliminating competition for them.  Wouldn't be surprised if Trump has negotiated a cut of the added profits they will make.  It would appear that the USA economy, which was formerly run on free market principals, will now be centrally controlled and run by a handful of individuals in the White House.  Sort of like the former Soviet Union and we know how that turned out; low productivity and lots of corruption.