Frogboy, would you mind sharing your views? =P I never think of a gamedeveloper/publisher as a republican, much less to the right of them.
Most business people are right of center. Not because they embrace the Republican platform but because of economic freedom - the ability for individuals to enter into agreements without the government interfering as well as government confiscation of capital. So to some of us, the left are the villains, just villains with good intentions. 
As for the backstory, it is indeed very important to the Sins universe.
The Vasari, for example, would utteryl overwhelm the humans entirely if it weren't for the fact that the entire TEC is only dealing with a tiny fraction of of the remnants of the Vasari Empire which was a vast, VAST interstellar empire.
The exiling of what became the Advent really understates the turmoil going on in human society at the time of Sins of a Solar Empire. Should humans intervene directly into their own evolution? It was a massive issue 1,000 years ago with the overwhelming majority believing that it was a dangerous path to take. If everyone began doing genetic modivications to themselves, you would have a massive arms race in ethically iffy genetic manipulation.
Even within 1,000 years, the Advent are only human by the most generous terms. It isn't even known whether the Advent and humans (TEC) are still biologically compatible.
What I really like about the Sins backstory is that it is quite plausible in many respects. One can imagine what will happen here on Earth within the next 1,000 years as we discover ways of modifying our own DNA and improving ourselves. We might be surprised how rapidly humans begin to chance, as a species, once we start modifying ourselves.
For example, did you know a huge chunk of our DNA is reserved for the sense of smell? But that DNA is currently unused, disabled due to a genetic mutation that occurred within the last few million years. It wouldn't be that hard to turn it back on and suddenly you'd have humans who could smell as well as other types of mammals (I wouldn't want to have that done to me but to a new born, it would give them advantages). There are all kinds of other traits that we can probably modify within the next 20 years that could have a massive impact on the future of society.
And so that issue finally came to a head in Sins of a Solar Empire's universe. Which direction were humans going to take? Unrestricted genetic and cybernetic modification? Or not? The zealots that became the Advent were exiled into the deep reaches of space but didn't forget the wrongs (from their perspective).
I think you'll see the Sins story explored in great detail in future expansion packs and sequels.