For avowedly nonpartisan and nonideological reporters, examining the substance of a politician’s beliefs and policy views is a professional minefield: The more deeply they venture into it, the more open they are to accusations of bias. The benefits of this dilemma mostly accrue to politicians. If reporters spent too much time on the comfortably nonpartisan foibles of Reagan’s “Reaganisms,” they spent too little looking closely at his advisers’ devotion to supply-side economics.
The gaffe, then, is a safety mechanism. It moves a statement from the realm of substance to the realm of performance and strategy — allowing the reporters to critique it without incriminating themselves professionally. To say that Trump’s views on immigration are inhumane, or self-defeating from the standpoint of the economy or national security, might hint at a subjective opinion on the part of the reporter. An easier problem to identify is that, spoken aloud, those views may hurt him with electorally important constituencies, or reflect poorly on his ability to stay “on message” in the manner expected of politicians. A rational candidate would not deliberately do something that unnecessarily jeopardizes his chances of victory, so it follows that the outburst must have been a mistake — a gaffe.
This of course bears little resemblance to how actual voters, pro- or anti-Trump, assess his words. In that sense, Trump really does have more in common with voters than he does with political elites. His inability to apologize or back down has opened the door to a post-gaffe politics, stripping away the convenient fiction of missteps and errors that journalists turn to when they are uncomfortable confronting a statement on its merits.