I wouldn't be able to vote for a president in the USA any more than I can vote for the Prime Minister of Canada. These are decisions made within political parties, and as part of that political center that overlaps both parties in the United States and many parties in Canada, I wouldn't be able to sign up to vote in the primaries.
The issues I am most interested in are not issues where any of the political parties, whether in the United States or in Canada, have a better direction. It all comes down to individual representatives that are elected, so I largely ignore the party banners when deciding who I would vote for. In Canada I have donated money to Charlie Angus twice already, even though I don't vote in his riding, and have never voted for his party (NDP).
I have spent much of the last decade fighting against the Clinton/Gore policies that sparked the current Copyright, Net Neutrality and related technology and economic debates. Everything I have heard from the Hillary campaign is that she has the same ties to the incumbent telecom, broadcasting, recording, motion picture and software manufacturing special interests I have been fighting against.
Obama is different in that he has even invited people like Lessig to help him on technology law policy. He has endorsed content from the debates should be licensed to allow citizen participation through remixing, something opposed by the Copyright maximalist special interests within the Demorcat party.
As part of the debate about who makes the best Tech President, others like Techcrunch have articulated why it is harder to analyze the potential candidates for the Republicans. There isn't as clear a winner or looser when it comes to new economy and technology policy. Techcrunch endorsed McCain, who even admitted that he was “illiterate” when it comes to computers.
I will be excited about the ongoing US presidential election as long as Obama is in the race, but otherwise won't really care which of the "Republicrats" wins the presidency.