What would be the point of manipulating the data used to make a prediction? How would that influence the final event - the number of votes cast?
Seems like if you have the ability or money to influence the search traffic, you could find plenty of other areas related to the election where you would get a higher rate of return.
Political entities try to create an air of inevitability for their eventual victory. You can see this at work right now in the spinning of various polls.
Manipulating the data used to create a prediction is a variation on that theme. If they could reliably do it, they would.
Influencing search traffic statistics could be done pretty low-cost, so the return wouldn't have to be that high.
It's all part of the gestalt they try to build anyway.
Seems like if you have the ability or money to influence the search traffic, you could find plenty of other areas related to the election where you would get a higher rate of return.