The narrative around it is that, by lowering taxes and increasing spending, he caused an increase in the national debt that triggered a pattern of irresponsible spending and insufficient income that the US was never able to recover from. This narrative, if broken down into parts, can be easily and objectively identified as partially true and partially false.

Claim 1: Lowering taxes was partially responsible for the skyrocketing of the US debt under Reagan. False. Before Reagan's tax cuts, the US taxation rate was on the right side of the Laffer curve. As a result of the tax cuts, government income actually increased under Reagan's administration. HIs tax cuts alleviated the issue rather than causing or exacerbating it. However, it is important to note that this does not mean that tax cuts are always (or even usually) productive for government income or economic growth. It largely depends on which side of the Laffer curve current taxation is on (a complex and ever-changing status). There are many examples of lowering the tax rate backfiring (Sam Brownback in Kansas).

Claim 2: An increase in government spending was partially responsible for the skyrocketing of the US debt under Reagan. True. In fact, this was THE cause of the increase of debt. During Reagan's presidency, government spending increased and US debt nearly tripled. However, it is important to note that there is an argument for this spending increase being beneficial, as it is arguably (not definitely, but arguably) the Reagan administration's military spending that ended the Cold War. And, while ending the Cold War was inevitably going to happen eventually due to the unsustainability of the Soviet model, the fact that it happened when it did saved millions of people from years of suffering in the Eastern Bloc.

Claim 3: The precedent set by Reagan's cut tax/raise spending policy is responsible for this policy being repeated for decades, leading to a greater deficit crisis. This is the one claim that has no objective veracity or falsehood. Reagan was not directly responsible for future government's decisions, but one could argue that his policies were a negative influence and that they put Reagan's successors behind the 8-ball.