The following is a fairly vivid example of why people want to see crosstabs whenever possible when it comes to polls:
The above is from a just-released AP-GfK poll; as you can see, it shows Obama up by one (47-46) over Romney in a poll of likely voters. Bad news for Obama, as the intent was that he was supposed to be opening up a lead at this point; not so great news for Romney either, since the D+4 sample is a lot more likely to be reflective of the actual voting electorate in November than the D+7 or higher nonsense that we’ve been seeing lately. But that’s another post.
What’s interesting here is the dramatic shift that takes place between the Adult/Registered voters and the Likely ones – and yes, Obama going from a double digit lead among the first, and a pretty-much-tied in the second, qualifies as ‘dramatic.’ As does the eleven to four shift towards the Republicans in partisan identification. This is what you’d expect to see in an environment where both sides have about equal shares of the electorate, but one side is considerably more enthusiastic about voting than the other. And that’s an environment that is kind of inimical to the party that has the more unenthusiastic partisans.
None of this should be taken as a rah-rah, Romney is going to win the election kind of post (although, yes: rah-rah, and Romney is going to win the election); rather, it should be seen as me noting that it is not unreasonable to be asking questions about voter enthusiasm, this go-round. We keep seeing evidence that the Democrats are not performing at anywhere near their 2008 levels; and that Republicans are performing… not too far off from their 2010 levels. People can be as happy or sad about either possibility as they like, but they should still recognize that the phenomenon is going on.