Sentence:  It's what known in the polling industry as “<WSD>herding</WSD>”. And <WSD>herding</WSD>, not to put too fine a point on it, is when pollsters cheat. Each polling company knows that however accurate their results are, they will ultimately only be judged on one poll. The final poll before the election. 
Meaning of the word marked with <WSD> tags:  Manipulation of (poll) results by a polling organization so that they match those produced from other organizations.