Texas doesn't have any right to succeed, nor does other such as California, Oregon, Hawaii.... the republican model doesn't mean you have a right to leave the union, it was a condition for statehood prior to becoming a state- and Texas was a model for this- it was a bootleg sovereign nation, and is hardly unique in this respect.
Even if the supreme court all dropped a shitload of acid and ruled in favor of some phantom right of succession ONLY on Texas' part, any local military officer would quickly point out that Texas got it's ass whooped during the Civil War, like the rest of the Confederacy, and this issue is now mute.
Texas however does have the right to disintegrate into five separate states, a biproduct of the split of the slaves vs free states era.... though slavery is now illegal, this aspect of the law stands independent of it's original cause that put it into being. At any time, we can end up with 5 Texas with 10 senators. Now.... I've always found this as odd as nothing prohibits any other state from doing this as well.... they just need congressional recognition- which Texas got a long time ago.
Also, though NO state in the union can succeed, there is nothing prohibiting a state from getting voted out of the union involuntarily. Also, a state can 'migrate' moving it's border on one side very close to the next, then moving the other, again and again, and just meander until it's within a range of like, ten feet within the territorial borders of Washington, DC, with a P.O. Box sitting under it's flagpole with 13,000 people signed up to claiming residency (if the Post Master General so chooses to allow this option for residency requirements in some states P.O. Box is all you need in the rural areas). The military does something similar, we like, next to never get rid of military divisions or whole regiments, the division is stripped of near all it's men, they're told what the traditions and standards and history are for it, and some other made up bullshit, and it's headquarters staff, including some specialty lower ranking enlisted guys such as Artillery Forward Observers, are sometimes added- they then tend to bullshit flags that no one actually serves under, and receive a reduced pay and MTOW from Congress. The job is bullshit, but their always busy, as the pentagon taps them as slave labor- as they all have specialties or high rank, and quickly become bitches to random people.
Also, a state can technically 'lose' it's statehood requirements if it's population falls beneath it's requirements to join. Some such as Alaska and North Dakota in the past, before their respective oil books, were facing the legal and deeply unwanted census listing of once occupied land becoming frontier again! They won't give you shit for moving there now these days though just for the sake of keeping their population up, they both have too many people in relation to infrastructure, why rent exploded in both places.
Now..... Alaska was bought from Russia (Clinton was offered to by the Chamchaka Peninsula from Russia and foolishly said no- just like Alaska).... Russia pissed off the natives there, and when the territory was bought over to US Sovereignty, it was made a military colony. You would think this would of made them resentful, but you gotta remember the nature of the average American of that era- mostly tough, independent frontiersmen...... who liked to hunt and fish.... which the locals liked to do in Alaska, and there was hardly any squabble over land, as what the Russians had built township wise was accepted by the locals, and largely populated by them. Anchorage was mostly useless land no one used- and it became it's main city, so there isn't any hurt feelings on this part. Living under military law was a blast back then.... as the military just largely didn't give a fuck about interfering when they could go skiing or hunting instead. Locals increasingly prospered, and became Americanized without much of a squabble. Not really much of a reason for a soldier to go hike out to a igloo and fuck around with it anyway, so it was a easy decision.
Now it's a state, it also hosts two army infantry brigades, several airforce bases, several anti ballistic missile testing sites, and like 8 marines who don't know how to swim. Most relations between the locals and the military is tight, and the military guys tend to date and marry the local girls, settle down, and add to the genepool- so many men in Alaska are either military or military descent.
The Marshall Islands succeeded from the US in 1986. We didn't really care, as we had control of Wake Island long before them.... and we never technically conquered them, just collateral from the war era. Marshall Islanders, known as Micronesians here in Hawaii, are the most hated Ethnicity period by the locals, and it's odd in some ways, as they're related to the hawaiian natives. Because we tested nuclear weapons on bikini atoll, the residents of the Marshall Islands are allowed 2000 per child every couple have, the right to move to the US, fast track to citizenship, and access to training schools. Many come here to Hawaii, and start a baby factory, and show up their first day and buy a Lexus. This causes a KKK mentality amongst the Chinese and Native population, raving about pregnant Micronesians fucking and making more babies.... something you won't here any other group say openly in any other part of the US, though I suspect every race has it's pet peeves and thinks this in a majority sense from time to time.... here it's rife.
The US, I think gave up Palau as well.... I can't recall right now.... they make decent tourist dollars due to Jellyfish lake. America Samoa might not be able to succeed because technically it's not a territory. We never actually conquered them, rather, we scared a German ship off from conquering them, and stationed some guys there during WW2 to keep the Japs off.... the locals learned how to fight form the GIs, and formed their own national guard unit. They have federal level representation and directives from the President such as in homeland security, but also are allowed 1 non-voting representative who acts within the capacity of a territorial representative.... pretty much what he says goes in regards to what happens to America Samoa. America Samoa, unlike a territory, does not have a territorial governor appointed over it, they elect their own president, who appears to be fairly independent as a president of a country goes, and claims American Samoa is indeed independent.... but this is also weird to say when there is a US flag outside, US military post manned (though almost exclusively by locals,) and several US Post Offices and federal buildings representing various branches of the federal government. In America Samoa, your not born with automatic American Citizenship, but it's silly easy to get it if you want it. There is a seperatist movement not so much from the US but from America Samoa on one of it's islands, but his shotgun is malfunctioning, so it's not a heated issue at this moment.
We have some territories in the Caribbean, both have the right to leave the union. Diego Garcia in the Indian Ocean is legally England's, though we'll someday likely trade them something for it, as we have a history of doing that. Guantanamo Bay is by treaty legally part of Cuba, but it was signed with a legally different Cuba, and the treaty is technically not as a result in force anymore due to Fidel Castro killing off that Cuba. But none the less, due to a Supreme Court loophole in rejecting it's jurisdiction over Guantanamo, it belongs to someone NOT America, and since we're still abiding by our end of the treaty, we're not in default.... though it's questionable legally who we can be in default to, as we're not required by international law to recognize the new entity of Cuba as a continuation of the old Cuba anymore than Russia was required to recognize Napoleon's France as a continuation of Monarchical France in which it had several alliances with.
We are able to freely give and sell off territories to whoever we want to. This includes Washington, DC....... congress can decide to sell it off quite legally, or give it up in a treaty in a heartbeat without much legal fuss.