Polls taken five months before a general election don’t have much value. It’s kind of like picking a World Series winner based on standings in May -- there are a lot of games to be played, and a lot can happen. Cheesy baseball metaphors aside, the folks over at MSNBC’s First Read bring up an interesting dynamic to keep an eye on as the press trots out poll after poll this campaign season.

In the 2004 race, First Read reports that George W. Bush never trailed John Kerry in any of the NBC/Wall Street Journal polls taken from March to October, but also never opened a lead greater than 4 points. Bush went on to win the general election by 3 points, 51-48 percent.

In the latest NBC/WSJ poll released Wednesday, Barack Obama holds a 47 to 41 percent lead over John McCain among registered voters. A look back at the March NBC/WSJ shows Obama leading McCain by 3 points in a hypothetical matchup.

Meaningful? Well, almost certainly not. But it might make these polls something to watch anyhow, in between checking the baseball box scores.