Possibly, but it's also a timeliness thing. This stuff has a window of opportunity: for like a week after the interview, it'll successfully game the results, but after that they may be crowded out by the reporting on the gaming itself.

If he's trying to spike negative results for just a certain period of time, it's quite an effective tactic. News cycles quickly, so even if each instance is eventually caught, it may successfully push down recent news / current events until they're no longer current, which may result in millions of people missing the reporting.