Well, the dysfunction we're talking about is coming from a number of places.
What's most immediately obvious is that there's a total blowhard in the Oval Office who has no idea what he's doing but all the confidence in the world. He has degraded important alliances, seriously enflamed tensions within the country, and inclined swaths of people against truth and reason. That's bad.
Less obvious but perhaps more pernicious are the traumas we're enduring thanks to American capitalism. The media has a profit motivation, so everything is super sensationalized to the point that there's a degree of legitimate doubt around mainstream news sources in addition to the manufactured doubt Trump has help stir. Add to that the extremely uneven geographic distribution of capital we're currently seeing and it's a recipe for disaster. This is what will take the country down, and it's exacerbated by Trump... but also independent from him, and even from the Republican Party. That's why I don't see things falling off the cliff under Trump, but if trends continue I wouldn't be shocked to see America become a shell of its former self within the next 60 years.
What's a "shell"? Some people say it already is.
Wider-spread poverty, virtually no economic mobility, near total automation of manual-labour and service jobs, total concentration of wealth in the metropoles which have been nearly completely gentrified... Hunger Games without the Hunger Games, and the oppressed majority is way more stupid.