Donald Trump is a weak president. He remains a weak president after the passage of tax reform, despite what some in the media are describing as a presidential “victory.”
Political scientists generally measure a president’s power according to his ability to influence public policy outcomes compared to past presidents or contemporary actors, like Congress. A strong president sets the legislative agenda, passes policies reflecting his preferences, and secures bureaucratic action on his governing priorities. A weak president has difficulty achieving these things, as competing political actors impede his goals and jockey to assert their own influence.
In his classic 1960 book Presidential Power and the Modern Presidents, Richard Neustadt famously defined presidential power as “the power to persuade.” A president must convince other political actors that their own interests lie in going along with him, or at least not standing in his way, Neustadt suggested.
The media is crediting him with a tax overhaul victory. But he still holds remarkably little clout in Washington.