How did the G.O.P. get to this point? On budget issues, the proximate source of the party’s troubles lies in the decision to turn the formulation of fiscal policy over to a con man. Representative Paul Ryan, the chairman of the House Budget Committee, has always been a magic-asterisk kind of guy — someone who makes big claims about having a plan to slash deficits, but refuses to spell out any of the all-important details. Back in 2011 the Congressional Budget Office, in evaluating one of Mr. Ryan’s plans, came close to open sarcasm; it described the extreme spending cuts Mr. Ryan was assuming, then remarked, tersely, “No proposals were specified that would generate that path.”

What’s happening now is that the G.O.P. is trying to convert Mr. Ryan’s big talk into actual legislation — and is finding, unsurprisingly, that it can’t be done. Yet Republicans aren’t willing to face up to that reality. Instead, they’re just running away.

When it comes to fiscal policy, then, Republicans have fallen victim to their own con game. And I would argue that something similar explains how the party lost its way, not just on fiscal policy, but on everything.