[reddog]

I don't know. Look at Canada; separated by the same distance yet it remained a colony until 1931.

While rebellious space colonies has been a dependable sci-fi trope since the 50's, I am skeptical things would really work out that way given how dependent Mars would be on Earth for everything other than the very basics of self-sufficiency. I am talking about things like art (music, books, films) and the kinds of developments in science, medicine and engineering that can only be generated by having a support base of 8 billion people.

[Qqqwxs]

I think it also depends on what flag the Mars colony flies. If a country (e.g. the U.S) claims the colony for themselves, I think it makes sense that there will be more and more pressure to disassociate especially as people from different countries on Earth mix together. I can see a united colony, however, something like the ISS, working better as there is the cultural idea of being "for humanity" as opposed to "for this country that not everybody identifies with".