I could maybe understand why people voted for the anti-establishment candidate the first time around. Legitimate frustrations exist with a system many felt wasn't working for them. But the second time around, with clear evidence of the consequences, is not defensible and shouldn't be excused.
This is a form of reactionary populism and it's deeply dangerous for the US's power, prosperity, and political freedoms. Ask Argentinians what Peronism, as another form of anti-establishment populism, did for them. There are countless other examples to learn from too.