Again, look, I fully expect, when historians take a look back at this time, Trump's gonna fill a slot on damn near all of their "worst 10 Presidents" lists for a very long time. [EDIT, restore accidentally omitted sentence] But we're not anywhere near failed-state territory.
However, sometimes history happens fast and maybe this time next year the US will actually be a failed state and the military won't be getting paychecks and will have disbanded or set up fiefdoms, and cartels will have de facto annexed Texas into the quasi-narco-state of Mexico that they already essentially co-govern, because no-one can stop them, and all our corporations will have scrambled chaotically to find ways to maintain continuity of operation and ownership of capital while moving to corporate structures overseas (incorporation, being a legal construct created by a given government, is worthless if it's granted by a failed state).
That is what happens in a failed state, and if we become one, that's what will be happening. It is not what is happening now.
But probably not. I dunno, I remember when everyone was sure Junior would try to become a dictator. Believe it or not the "other" side was exactly as sure that Obama would, too. I get that Trump is actually making public moves to screw with voting and doing all manner of other awful things, but I think one can be reasonably concerned about and upset by these things but also acknowledge that it's incredibly unlikely—not impossible, unlikely—that "failed state" will be an accurate term to apply to the US any time soon.
Also sometimes I go read Wikipedia's summary of history for various years, going through maybe a decade in a sitting, to gain some perspective. Remember that time we killed a few hundred thousand of one another over the right to own humans as property? That was a bad one. And holy shit the 1960s were another crazy '60s. Black people and Episcopalians being straight-up murdered because they took part in civil rights protests, and I don't just mean by cops or by counter-protesters at the protests but by people later, in cold blood, for having participated in them. Quakers self-immolating in protest of the draft. Told a bunch of 18 year olds we were gonna stick them on ships and planes and send them to the other side of the world to die an/or become killers in some jungle over a war we lied ourselves into, and if they didn't like that they could rot in jail. That decade sucked, too. Good music, though. Lots of decades of US history are full of shockingly bad political stuff and strife. Most, maybe.
[EDIT] maybe this provides a clear test: if the US state fails then the Federal government will no longer be able to effectively secure its own nuclear arsenal, pretty much by definition. Someone might keep them secure, but it wouldn't be the Federal government. If security of the bulk of the US nuclear arsenal is not yet something that a wide variety of foreign state and NGO actors are getting acutely nervous about, then you can be pretty sure the US is not yet a failed state. And no by security I don't mean worries about Trump having the big red button, I mean worries that anyone might walk in and take one, or the people guarding them might sell them, like everyone was worried about when the USSR collapsed.