Wait, Now Scott Brown's Ahead?

Image via The Newseum

So Elizabeth Warren is either racing ahead of her opponent Senator Scott Brown with as much as an six point lead, or, as the front page of Thursday’s Herald triumphantly asserts, Scott Brown is comfortably leading Warren by six points. That’s right, even after four polls found small leads for Warren this week, a new Herald/UMass poll finds Brown ahead 50-44. Right about now, you’d be justified to ask yourself, “What gives with these polls?”

Well first, take heart that confusion and wildly varied results aren’t limited to the Massachusetts Senate race. As New York Times whiz Nate Silver tweeted Wednesday, “The. Polls. Have. Stopped. Making. Any. Sense.”

The other thing to note is that there is some fine print (or there should be) on the Herald‘s banner headline. They are leading with the numbers that give Brown a six point lead among registered voters. Most of this week’s polls have led off with the poll of likely voters. Looking at those, the Herald still finds Brown in the lead, but by four points which is within the poll’s margin of error of +/- 5.5 percent. (Many of Warren’s favorable polls this week were also within the margin.)

This outlier poll is actually a helpful reminder that despite all Warren’s positive headlines, and signs that her strategy of nationalizing the race is starting to work, each individual poll is actually only taking a fairly small sample size, and all of them have had fairly large margins of error. As they start coming in fast and furious, we’ll need to avoid investing too much faith in any one set of numbers. As the Huffington Post’s Mark Blumenthal writes this morning:

Relatively small sample sizes likely contribute to the variation. All but one of the new surveys sampled from 400 to 600 likely voters, for reported margins of error ranging from +/- 4 percent to +/- 5 percent.

Especially with today’s addition, the race still looks fairly tight going into the debates, the first of which airs tonight.