They certainly can—or at least, some people want them to. Many groups and leaders, both in England and elsewhere in time and space, have sought to strengthen or instill a national identity on the basis of common (recent) biological ancestry.
You’ve changed the subject there. 
The comparison was with EU nations, not with constituent countries within the UK. It went like this (you saying that US states were the same as EU nations):
**Floater: **The EU is a cooperation between sovereign nations, each with its own legislation (although sometimes EU regulations supersede national laws), and nobody would claim to be a citizen of the EU, whereas Americans are citizens of the USA.
**You: ** In that vein, the USA is a cooperation between sovereign states, each with its own legislature (although sometimes US regulations supersede state laws). It wasn’t that long ago that people were from their state first, and the country second. “States” in “United States” does not mean “province.”
**Me: **Florida can’t enter into a treaty with Japan, or declare war on Italy (or, for that matter, can it declare war on California). Florida does not have sovereign power. EU countries do.
Logical, yes, but also another layer of bureacracy, and another set of politicians’ wages to pay.
Thinking about it, I wonder how much parliamentary time is spent on matters purely pertaining to England (and Wales, as many laws apply to both) as opposed to the UK as a whole? Quite a bit, I should imagine.
I’m not sure federations work very well when there’s one dominant member. The Westminster parliament already is quite close to being an English parliament, which is precisely why the Scots and Welsh demanded their own assemblies. It’s difficult to see what purpose another, purely English, parliament would serve that is not already well-served by Westminster. Perhaps you could have a constitutional amendment to bar non-English members from voting on measures that only or primarily affect England, but I’m not sure how you would define that.
Dr. Drake, you’re talking about ancient tribes, which has little to do with contemporary Britain, whose ethnic roots are are a lot wider than “Celts, Romans, Anglo-Saxons”, yes, even in far-flung Cornwall. It seems to me that “Cornish nationalism” (a term I have never heard so had to make up) is being hugely overstated in this thread. Most people who live in Cornwall have heard of the outside world. Indeed, many of them come from it. The Cornish-pride thing, it seems to me, is slightly tongue-in-cheek except among a very small number of nutters. A bit like people putting confederate flag stickers on their bumpers - they don’t actually mean that they want southern states to secede from the Union. They’re just expressing a bit of pride in their home state or region.
Perhaps we can find a Cornish Doper, pin them down and ask them who they support in international football. That should settle it once and for all 
It would also raise difficulties on confidence matters, if the government only had a narrow majority in the House and its members from Scotland and Wales could not vote - suddenly the government may not have the confidence of the House for “English” matters, but would have the confidence of the House for “British” matters - would be very difficult to make it work, I would think.
The old Province of Canada experimented with a similar approach in the early 1860s - the “double majority” - that anything that affected both Canada West and Canada East had to have a majority of the members from both regions supporting it to pass. It proved unworkable.
Cornwall is just as modern as the rest of Britain. Nobody said otherwise. Cornish nationalism is a real thing, including violent agitation for a separate Cornwall, but that is only a very small part of some people’s Cornish ethnicity and certainly not representative of the whole. Cornish ethnicity is simply the culture (customs, values, beliefs, behaviours, speech) of a specific group. It is distinct in origins from English culture, and meets all the criteria for an ethnicity bar distinct language, which has been lost in comparatively recent history and semi-successfully revived. I don’t know why this woud be controversial.
Actually I suspect this was more common than not. Spain is another excellent example. During Spain’s first great imperial phase it was the crown of Castile that financed the bulk of the Spanish Hapsburg’s wars, whereas other constituent parts like most prominently the crown of Aragon paid only a pittance because their tax laws and the rights of the kings were much different. And this legal seperation was the case for a very long time - from the union of the crowns in 1469 to the Nueva Planta decrees in the early 18th century.
Or ask if he/she is pro- or anti-stargazy pie! 
Also the situation around the UK, you have the Channel Islands and the Isle of Man which are ruled over by the Queen (or King) but are not part of the United Kingdom.
And then you have the situation where the king of Spain (which was an amalgamation of various kingdoms) was also king of Portugal, but somehow Spain and Portugal never amalgamated into one Iberian kingdom.
If we’re going to do this, English and British are mutually exclusive concepts: It’s impossible to be Brythonic and of the Angles, a Germanic tribe, at the same time.
Yes, this is what I was referring to. Germany, Spain et cetera were made of countries, but those old countries aren’t considered countries any longer. The UK is made up of four places that still call themselves countries. I just found that a tad confusing.
Politically you’re wrong. Economically, in some ways, you’re right. EU competition laws are tighter, and there are stricter rules governing the ability of EU countries to ban products or services.
Barcelona <> Catalonia. There were many different, independent Counts in Catalonia - which was a geographical and cultural concept, but not a political one.
I regard myself as British and Scottish (in that order).
When I am in the UK, I’d say I was British, but when I am overseas, I’d say that I was Scottish. I think this has to do with most people confusing British with English. I am British, but I am not English (if you see what I mean).
In Scotland, some people regard themselves as British and Scottish, some Scottish and British, some just Scottish and some Irish (mainly due to religious reasons). Of course, this spectrum can make politics quite complicated.
If the UK decided it wanted to become a federal state, I suspect the thing to do would be to divide England up into several regions, each with its own assembly or parliament. From Wikipedia, Scotland has a population of around 5.2 million; Wales, 3 million; and Northern Ireland, 1.8 million; whereas England has a total population of 51.6 million. So, to properly federalize the UK, you’d divide England into at least a dozen regions. The Union parliament would presumably continue to handle stuff like defense (pardon me, defence), foreign relations, and the currency (assuming Federal UK doesn’t join the Eurozone); the governments of the federal regions (Scotland, Wales, Northern Ireland, and the new English ones like Yorkshire or East Anglia, and maybe including Cornwall) would handle local affairs (education, police, and so on).
Bear in mind that Britain is not a confederation of equals.
Economically and culturally England is overwhelmingly dominant, with Wales ($85bn) and Scotland ($194bn) contributing a fraction of England ($2.2tn) to the UK’s overall GDP.
Even when the differing population numbers are taken into account, England still generates a higher GDP per capita than either Wales or Scotland.
It’s therefore not unreasonable for other nations to equate “Britian” with “England”, even though it causes understandable resentment to the Scots and the Welsh.
Both are the main reasons that the English don’t really want an English Parliament/Assembly, apart from the English Democrats, whom no one cares about. The current Parliament in Westminster represents (or ignores, depending on your viewpoint) English interests pretty thoroughly. The idea of regional assemblies was also briefly considered and deemed stupid for the same reasons.
Instead, England are going with a mayoral model for the big urban areas (London has had a mayor for, what, ten years or so now) which should cover the majority of the population.
Wilifred the Hairy, (Guifre el Pelos) though, managed to unify almost all the Catalan counties.