And to expand on **Bytegeist[/]b’s answer, not only can states not have treaties, they can’t have laws that effect foreign policy either.
Just supposing all this came to pass…the political landscape of America would be massively changed. With a population of fifty million, I reckon that the State of England would get about 76 votes in the electoral college.
On the other hand suppose the USA got fed up of being top dog and decided to become a British colony again.
Would we let them or tell 'em to sling their hook 
But given current political alignments, those votes would have to be safe for the Democrats.
“Hello boys, I’m baaaaack”
Hardly - the Democrats are somewhere off to the right of the Tories. Three-party system, anyone?
Queen Maria I of Portugal. But she was insane and her son ruled as regent.
Tony Blair for President? (Although he’s unpopular in the UK, he’d win the UK vote against anyone the Democrats would put up, and he’d be likely to carry quite a few blue states against the likely contenders in 2008).
are you mad sir?
Right. But, in practice, no member of Congress would want to lose a seat, so the House would be increased in size by 70-80 members, to allow the UK to get its share under the formula, while current states did not lose seats.
(However, I’m aware that the formula does some odd things at times, including allowing the size of Congress to increase, while a particular state loses a seat in the process (with no population change).
It would never happen- free movement would mean that the UK would become the new Florida- free medical treatment, free medication etc. for the snow birds. Additionally the UK (especially Scottish) University system would be over-run - no University fees for Scotland, and minimal ones for England and Wales.
We have enough problems with the rabid right complaining about Eastern Europeans, let alone Americans coming over and stealing our services. 
We’d have to have another capitol building.
As you can see the number of representatives hasn’t changed in 67 years.
(America is the most underrepresentated country in the world.)
Besides, they wouldn’t get any highway funds since they drive on the wrong side of the road.
Absent a constitutional amendment Blair would be ineligible for the presidency:
All previous new states have been formed out of United States territory, so the citizens of those states were already US citizens, with the exception of Texas (as far as I’m aware). So (except for Texans), they were generally already eligible to be elected as President. Oddly, they didn’t make any special rule for Texas: perhaps they were too few Texans for them to be considered, though since then two natural-born Texans (Eisenhower and Johnson) and one Governor of Texas (Bush II) jave become President.
As part of the complex changes required for the union of the two countries, I’m sure that it would make sense to add that natural-born citizens of the UK before the union (including HM the Queen, who is not a citizen and is not eligible to become Prime Minister) would be eligible to become President in the same way as natural-born citizens of the US.
U.S. states run their own individual school systems, separately, and there would be no particular need for your universities to change much. They would still design their own curricula, admit or reject students more or less at will (without violating federal discrimination laws of course), and fund themselves however they were able.
Many American universities charge students differently based on state of residence — which unfortunately, for the out-of-state student, is difficult to change quickly. So UK universities could continue charging little or nothing for in-state students, and exorbitant fees for out-of-state students, if that’s what they wanted to do.
Universities charge no fees based on Scottish residency, not the location of the university. And Scots get to pay less for all universities in the UK. So I imagine (assuming a similar situation is set up with the other states) you’d in fact get a lot more Scots moving out to the higher-charging colleges in the rest of the U.S.
I thought it was the other way around, that the Scottish Parliament decided to fund the full cost of HE for Scottish-resident students, wherever in the UK they study? (In other words, the university fees which are paid by English students are paid on behalf of Scottish ones.) Which, I presume, any state would be free to choose to do in the USA.
Yes, that was very badly put by me. It’s whether or not you’re Scottish that means you don’t have to pay, not going to a Scottish university. I as a resident of London would have to pay to go to Edinburgh University, but a resident of Edinburgh would have their fees paid totally by the Scottish parliament if they went to Edinburgh Uni., and paid in part if they went to a London university.
And, arguably, Vermont. Hawaii was annexed long before it was made a state. Vermont declared itself a republic in 1777. It became a state in 1791. It can be asserted that it was a republic only because the newly formed United States had bigger fish to fry than concerning itself with the status of Vermont, and the British had washed their hands of the area after the American Revolution. Some historians note that it was a “reluctant republic”, setting up shop on its own only because the US couldn’t get its act together concerning how to admit them as a new state, which is what a majority of the population wanted (there were also factions which wanted to remain independent, or petition to join Canada). The US didn’t admit them until they were prepared to also admit slave state Kentucky as a counterbalance (Vermont’s 1777 constitution had explicitly outlawed slavery).