Around 85 million people tuned in to watch the first Clinton versus Trump debate. Although this is a staggering audience, and upcoming debates may be expected to attract a similar number of viewers, televised debates don't matter as much as we think. Consider the fact that there is not much agreement on the outcome of the first debate, and even the biggest win awarded to either candidate (a 4% gain to Clinton) is still within the margin of error for an election prediction.
To be sure, nothing would suit the media more than a critical incident that ends up influencing the election result, and it has happened before: e.g., Nixon's sweat, Al Gore's sighing, or Reagan's jokes. The problem with such incidents is that, contrary to popular belief and the media's wishes, they reveal very little about a candidate's actual presidential potential. Just because we live in an age of media politics does not mean that what we really need is an entertainer-in-chief rather than a competent leader!
And yet, both candidates will do what they can to make the most of the next debates. The stakes are obviously very high, but the chances of successfully influencing pubic opinion - and shifting votes - are rather lower. In that sense presidential debates are like playing the lottery: there's a big prize for winning but no clear formula for winning the prize.
The best candidates can do, and one can only imagine that an army of spin doctors and PR consultants is working full-time to help them achieve this, is to effectively manage their impressions. That is, to carefully craft their message and behaviors so as to upgrade their reputation with viewers, in particular undecided voters.
Although this is more art than science, here are a few evidence-based recommendations that the candidates may wish to consider to win the next debate:
What Clinton Could Do to Win:
Clinton's biggest problem is that many voters don't have a clear understanding of who she is. Politicians are like brands, and the stronger they are the more clearly they convey the attributes and style that makes them different from others. Whether you like Trump or not, it is very easy to understand what he stands for, and despite his alleged improvised style his behavior is fairly predictable, which is an asset when it comes to attracting votes. Thus the best strategy for Clinton is to repeat the same strategy she used during the first debate, where she combined the traditional style of a mainstream politician with some seemingly engineered calmness and humor. The Trump campaign will no doubt attack her for being overly scripted and "inauthentic", but that is what politicians are. If Clinton can demonstrate that over three debates this strategy is sufficient to resist Trump's attacks and even unsettle him, she may win some more votes.
Another perceived weakness that Clinton should try to address is her alleged emotionality. Perhaps because she is a woman, many viewers including traditional democrat voters perceive that Clinton is too emotionally sensitive and vulnerable to be president, which questions her ability to handle pressure. Conversely, Trump's overconfident style plus his incomparable ability to draw media attention may suggest that he is immune to pressure. The best Clinton can do to persuade skeptics that she is mentally tough enough is to avoid reacting to Trump's provocations. She managed to do this well during the first debate, responding to most provocations with a smile, and appearing to expect them. The same approach should work again - the calmer she stays, the more annoyed Trump will get, which will turn his aggression against him.
A final point Clinton may want to consider is how she can expose Trump's weaknesses. From the first debate we have learned that his biggest deficits are in the area of content: Trump appeared to run out of ideas (and started repeating himself) after the first 30 minutes. The split screen also portrayed him as fairly out of depth with regards to technical facts, as if she could make stuff up without him noticing. Although it is true that voters appear not to care much about accuracy these days, just like Trump will attempt to make Clinton look irritable and emotionally vulnerable, Clinton should attempt to make Trump seem uninformed. Few qualities are more important for leadership than good judgment, and while Trump may benefit from not having a record as a politician it is hard to demonstrate potential for leadership in the absence of knowledge and expertise.
What Trump Could Do to Win:
The most effective strategy pursued by Trump during the first debate was to remind viewers that whatever Clinton says she is just a politician. This would work on his favor again given that most people around the world are disenchanted with the political establishment and, whatever Clinton does or says, she is clearly an emblematic member of that establishment. Since Trump's biggest asset is not being a politician, and Clinton cannot pretend not to be one, this is a strong card in Trump's hands. At the end of day, much like with Brexit, many people prefer a complete wild card than more of the same guaranteed - because they for sure are unhappy with the status quo.
In addition, Trump could do more to exploit Clinton's past records. During the first debate he seemed too unfocused and impatient to let Clinton respond to his criticisms (e.g., the e-mail scandal, her decisions as foreign secretary, and her changing views on key policy issues). Good leaders are seen as trustworthy, which comes as a byproduct of good judgment and integrity. Instead of threatening to talk about her husband's affairs or what she said about Obama when she campaigned against him, Trump should question Clinton about her track record. Past behavior is a good predictor of future behavior, and this is no doubt Trump's best weapon against Clinton.
Finally, for all the talks that Trump needs to appear more "presidential" - which presumably means seeming more composed, politically correct, and less aggressive - he has gotten this far for exactly the opposite reasons. It is indeed his outrageousness, unconventionality, and bravado that have helped him destroy his political opponents and gained an unexpectedly large and loyal support base. While it may be reassuring for undecided voters to see that Trump is less of a risk than his critics have stated, that case is now hard to make, for there is too much evidence for the contrary. In short, Trump needs to hope that he can still persuade undecided voters that an entertaining, over-the-top, TV personality is preferable to a conventional politician. If that is the case, then the last thing he would want is to seem presidential.