WASHINGTON — In his pledge to aggressively expand American oil and gas production, and his framing of that push as a salvation for the nation’s economic and fiscal health, Donald J. Trump is following in the footsteps of decades of Republican politicians.

But in a market where domestic oil production is already higher than it has been in 40 years, and natural gas production is at a historic high, those proposals have run up against a major problem: the global economy.

As the presumptive Republican nominee spoke in Bismarck, N.D., this week, in the booming Bakken oil fields not far away, oil and gas workers were actually being laid off, victims of their own success and the global energy glut they have helped produce. Plunging oil and gas prices have pointed to a fundamental flaw in Mr. Trump’s argument: At a certain point, production of oil and gas will push prices too low to justify even more production.

The Organization of Petroleum Exporting Countries — especially its leading producer, Saudi Arabia — also gets a say. If it decides to keep the spigot cranked, the bar for profitable American production gets higher, investment falls and the sector contracts, regardless of Mr. Trump’s intentions.