You know, just yesterday I was thinking, “If only we had more dubious polling metrics to sift through in this election.”

Sometimes dreams do come true, my friends.

Today, we’re launching the Twitter Political Index, a daily measurement of Twitter users’ feelings towards the candidates as expressed in nearly two million Tweets each week…

Each day, the Index evaluates and weighs the sentiment of Tweets mentioning Obama or Romney relative to the more than 400 million Tweets sent on all other topics. For example, a score of 73 for a candidate indicates that Tweets containing their name or account name are on average more positive than 73 percent of all Tweets…

For example, the trend in Twitter Political Index scores for President Obama over the last two years often parallel his approval ratings from Gallup, frequently even hinting at where the poll numbers are headed. But what’s more interesting are the periods when these data sets do not align, like when his daily scores following the raid that killed Osama bin Laden dropped off more quickly than his poll numbers, as the Twitter conversation returned to being more focused on economic issues.

Here’s their graph showing how Obama’s Gallup numbers stack up against his numbers in the “Twindex,” which has O at 51 and Romney at 26 as I write this. And yet, compare the current Twindex trends for the candidates since May…

…to HuffPo’s poll-of-polls trend over the same period:

Obama’s been inching up and over into net positive territory in the Twindex, but in the poll of polls it’s Romney who’s rising while O is flat. Hmmm.

As for why the Twindex might produce unscientific data, the Computerworld blog IDs three problems: (1) The pool of Twitter users who tweet about politics might not replicate the U.S. electorate the way a good scientific sample does, especially in swing states and especially since there are plenty of foreigners/non-voters tweeting about the election too; (2) the algorithms used to determine “positive” or “negative” sentiment in a tweet could be dicey; and (3) the more influential the Twindex becomes, the more partisan Twitter users will try to game it, especially given how easy it is to set up spam accounts. Even so, I’m not sure any of that matters. Political media can’t resist a new election metric or a new angle about how social media is influencing politics; put the two together and you’ve got a perfect recipe for navel-gazing stories about how Romney is gaining on Obama in the all-important Twitter race or whatever. (As a longtime InTrade linker, I’m guilty of this sort of navel-gazing too.) And the more important the Twitter race becomes, the more important “gaffes” and other minutiae will become since they’re apt to have the quickest and strongest effect on Twitter’s moving needle. This thing might be useful after one of the candidates gives a major speech to get a rough sense of how well it was received, but beyond that, I don’t know. Honestly, I’m polled-out.