Then colonization takes away from people the right of self determination as a culture? You must not forger, aswell, that Texas hasn't got the same cultural and historical differences that set appart Skyrim from the empire, It's closer to South America seceding from Spain or North America from England, that can not be argued.
It can be argued.. because The Empire started in skyrim, and all humans (except for redguard) came from Skyrim - they just changed into the imperials over the ages, presumably due to climate (bretons are humans with elf-blood) Just because different provinces have developed pretty differently doesn't mean that they all didn't originate from the same place. Tiber Septim AKA Talos was a Nord, and lead Nord armies.
So they're forced to take what the new Empire offers them without hesitation in the hopes of a better future? They must step aside and watch how their culture is traded by other people so they can save what's considered important for them? I think not, every man has the right of making his voice heard, lethargy is never good in politics.
Nothing about their culture is being 'traded' or stomped on - other than Talos worship, which is a huge part of the Empire's culture, too. The problem with the stormcloaks is they don't think "every man has the right to make his voice heard" but instead "every man has the right to support me, or die" - Ulfric says it himself : "They are either with us, or against us"
People keep mistakenly adding democratic overtones to the Stormcloaks, when they're anything but, simply because they go on about 'freedom'. Remember, Ulfric is taking the crown by force - he dueled the last king using dubious methods, and refuses to accept the traditional method for electing a High King - a moot of jarls, because many jarls consider his act of, or method of, killing the king to be foul (using a Shout). As such, Ulfric knows he won't win an election, so he's taking it by force. Ulfric will not accept, or allow, anyone who dissents against his crowning as High King to remain in power, or live.