Longtime readers know that a certain very close "friend" of the proprietor is a fan of political prediction markets, and in fact used such markets to win a nontrivial amount of money in the 2004 election. Awhile back, this same "friend" sent Tradesports.com an e-mail asking them to add a set of contracts to their available wagers on the 2008 Presidential Election and, kindly, they did.
Before, you could bet on who you think will be the Democratic or Republican nominee and you could bet on which party will win the Presidency, but not on who will win the Presidency. The reason my "friend" wanted them to add the last kind of wager is that with it, you can calculate the market's assessment of the relative strength of Hillary Clinton versus Someone Else as the Democratic Candidate. The relevant current market probabilities from Tradesports.com:
Probability that HC is the Democratic nominee: 42.0%
Probability that a Democrat wins the Presidency: 48.5%
Probability that HC wins the Presidency: 18.1%
So, what these numbers mean is that the market thinks the Democrats have a 43.1% chance of winning the Presidency if Clinton is nominated (18.1/42.0), compared to a 52.4% chance of winning if Clinton is not nominated ([.485-.181]/.58). If you think these numbers do not reflect the reality of the impact of Clinton on the Democrats' chances, you are of course entitled to your opinion. The great thing about prediction markets, though, is if your opinion is correct, you can make money off it.
(Given that I say things like "Hillary can't win," my own opinion is that the Clinton penalty to the Democrats is larger than what these numbers would indicate. My "friend" has not yet bet on my belief, however. I invite you to profit from my acumen, however.)