IBD/TIPP Daily Poll is Useless

We're obviously being buried at the moment with national tracking polls. On Thursday, for example, according to RCP's tracking there were no fewer than eight national polls released purporting to track the current state of the presidential race. All eight of these polls showed Obama to have a lead over McCain, but with the margin of victory for Obama ranged wildly from a high of 13% to a low of 1%. Fort the record, I do not in my wildest dreams think that Obama will win this thing by double digits as shown in the CBS/NY Times and ABC/Washington Post polls. I personally expect the real lead for Obama at the moment is somewhere in the 4 to 7 point range, consistent with five of the eight polls released on Thursday (see this one, that one, here, here and here). I do want to pick on the outlier for a second, the IBD/TIPP daily poll which shows Obama with just a one point lead.

After showing leads for Obama of 6% on Tuesday and 3.7% on Wednesday, the IBD/TIPP poll found a lead of just 1% on Thursday. Why did IBD/TIPP show a big shift in momentum over the past few days when no other pollster did? Well, it may have something to do with their samples being unrepresentative. I'm just guessing here since they don't give you any clue as to the demographic makeup of their sample.

Let's analyze the silliness a little more closely. IBD/TIPP doesn't share what percentage of their sample was between 18 and 24. They do, however, tell you what percentage of that age group voted for McCain vs Obama. The shift in the trend they showed over three days is striking:

Tuesday- Obama +6 points; 18-24 year olds- Obama 46% to 44%

Wednesday- Obama +3.7 points; 18-24 year olds- McCain 53% to 43%

Thursday- Obama +1 point; 18 -24 year olds- McCain 74% to 24%

TIPP touts itself as having been the most accurate pollster of the 2004 election. And, this daily tracking poll gets national attention on a daily basis via the popular RCP site. Yet, they present with a straight face data that shows a 52 point swing over three days in the 18-24 age group. Not to mention they also show a 20 point swing over three days among Catholics in favor of McCain and a 15 point swing among single women in McCain's favor.

So, is the race really tightening like IBD/TIP is claiming or is Obama's mid single digit lead holding pretty steady like just about every other pollster says? Given IBD/TIPP's apparently odd samples, I will guess that the latter is the case.