I will argue for the contrary, just to bring a few points to the discussion.
Firstly, the system of representative democracy (and earlier direct democracies like accent Greece) assumed that voters were, for the most part, equal. The extension of the franchise in Western democracies during the late 1800s to the middle 20th century brought that idea to its fullest egalitarian flowering, everyone was equal in right and before the law, so everyone was potentially eligible to vote. (there are a few restrictions, but these are generally more of the exception than the rule).
Uploaded personalities are quite clearly not equal to embodied humans. Their physical location is unclear (as pointed out), but more importantly, they will be operating at a subjective speed far greater than any embodies human. The difference in speed between electrical impulses and electrochemical impulses in the human nervous system is a factor of 1,000,000, so even the slowest uploaded individual will have far more time to research, consider, invest and otherwise do things than an embodied human. By the time your Member of Parliament or Congressman finished reading a document and signing it, "you" would have subjectively lived out perhaps a full 20 year career in virtual space. If you were the one who submitted a petition, then by the time it was read (much less actioned) the circumstances would have been long expired for you in virtual space.
The second thing to consider is that politics, as defined in Organizational Theory, is a means of allocating limited resources. Living in virtual space, uploaded people will have escaped much of the constraints of limited resources, and their key needs are really bandwidth, processor time and energy. A sympathetic human working outside the political arena can conceivably provide much of what a virtual community needs (erecting solar panels and installing a server farm in inexpensive properties scattered about, for example); the embodies human could be receiving stock market tips and patents to pay for their time and effort in return for very little investment of time by the virtual community.
The third thing to consider is that laws and regulations are means of encoding and regularizing people's behaviours according to the moral and social standards of the polity (Samuel Huntington's "Clash of Civilizations" brings this home by showing that different polities have very different ideas of concepts like Law, Justice, Rights and so on, hence the "Civilizational" clashes. A simple example might be to compare IP laws of the United States and China, and consider the wildly different interpretations of Intellectual Property between them). Uploaded people will have centuries of subjective time to consider different social, political, economic and religious ideas in virtual space, do experiments and "live" in communities that develop, practice and refine their own social and moral standards. A radically different sort of civilization might exist in virtual space; one which might consider the various rules and regulations (and social norms) we live under to be outmoded, barbaric and even counterproductive to the virtual civilization.
If anything, uploaded people will rapidly tire of interaction with the glacially slow real world and withdraw from interaction. A "Virtual revolution" may possibly take place, but this would require a great deal of preparation in the Virtual world to prevent being hacked, having malware introduced or simply having server farms destroyed and the power cut off. In a way this is similar to what I see happening if Strong AI is ever introduced; the AI will b e thinking so fast that we will rapidly be left behind and the AI will follow its interests and plans without reference to us.
I suspect that in the end, there will be a constitutional conference in the VR world where they more or less declare independence from the United States and no longer pay taxes or provide services except on a contract basis (and most likely on an individual to individual basis rather than government to government).
