Adam, when one has a world view, it’s easy to look at data that supports that world view — this is of course a general problem but seems to be dialed to 11 in Trump supporters. One could say that the boom during Clinton’s years were because of massive productivity gains ushered in by the internet. Similarly, the boom during Reagan’s years was certainly helped by incredible gains from the growth of personal computing. You claim that it was all undoubtedly the result of Reagan’s tax cuts and the peace dividend. It’s a position, and certainly not the most ridiculous hypothesis, but hardly undoubtable.
Surprisingly, you cite an article from the National Review whose entire premise is that you cannot assign economic performance during a President’s tenure to his policies. The author’s point is not that the gains in Clinton’s time were directly the result of Reagan’s policies, but that Ms. Clinton cannot claim that her husband can take full credit for the gains during his presidency.
Note that the US economy is a supertanker — you can certainly sink it, but hard to change it’s direction quickly. Sudden acts, like war, long-term structural stress (like 2007), or wonton acts of stupidity could immediately break it, but anything Trump or congress does will will take many months to have any tangible effect.