I think you just as well vote for Hillary and contribute to her campain if you can afford to do so, because barring some really surprising circumstance, she's going to win. At least then you'd have some influence?
The nomination system has become machine controlled in both parties to the point that the power brokers decide who is nominated. They have thousand of local "party managers" who push for the candidate that they are told should win. Their support is rewarded once the election is over. The Clintons and the Bushes will choose who comes in first and second in their respective party nominations. I have been surprised that the Bushes don't really seem to be that certain who they want on the republican ticket, more who they know they don't want (read McCain). He tried to find common ground with them, but something must have went wrong because now he's out. If they continue to hold back support for any particular candidate like the major dems did in '92 making way for Bill, then they may get a populist candidate that their chosen successor can not beat. That would be nice. It's not hard to see why they don't like any of the current Republican front runners.
As you can imagine, if the Bushes can get a complete unknown, inexperienced, and frankly completely unprepared candidate like Dubya nominated, then the Clintons will surely have no problem putting Hillary on the Dem ticket. They just had convince the middle Dems that she could win a general election, which the polls have done for them.
Whether anyone (especially Reps) like it or not, people seems to like Hillary the more they get to know her. As someone said to me the other day, she isn't at all what they thought she was. These silly attacks on her about hairstyles and airplanes, etc. by the Reps rumor machine will certainly fade by Nov '08. As far as her personal ambitions, no one runs for President of the United States unless they are at least clincal-level egomanical.
All that being said, I don't like her politics. In some ways she will be beneficial for the US, but she falls into the socialistic answer to a problem way to quickly (read It takes a Village - no really read it). Some problems are best solved by the federal government, and even some can only be solved by them. I would strongly prefer a candidate that looks for the least invasive means to acheive the needed resolution.
I can only hope that her years in Washington have taught her the importance of balance and mutual respect. I will give her credit for one thing. Most candidates that were leading the polls of the opposition party when the sitting President barely has favorable ratings IN HIS OWN PARTY, would be throwing the feces like a crack-addicted monkey. She has shown wise restraint. I may be overly optomistic here, but i believe she has made the decision that doing so would hurt the US in long run, even if it helped her. Is is possible that she is not selfish enough to take advantage where she can for the good of the country, even the world?