His announcement was greeted with something between incredulity (Trump has flirted with running many times before) and amazement (Trump is Trump). The prevailing sentiment seemed to be a collective eye roll and a laugh. That's the wrong reaction.
Trump's candidacy is a terrible thing for politics, plain and simple. Here's why: Trump can't and won't be ignored. Ever.
People like Marco Rubio, Jeb Bush, Scott Walker, Mike Huckabee and everyone else on that debate stage will be playing by one set of rules, Trump will be playing by another. Or, more accurately: Trump won't be playing by any rules. He won't be bound by time constraints put on the candidates. He won't be bound by the generally accepted rule that you try to offer policies that might have a chance of becoming law. He won't feel the need to strictly adhere to, well, the truth.
That lack of rule-following (or even an acknowledgment that rules exist) will ensure that Trump is a big part of any story written off of the debates or any other forum where multiple presidential candidates are present. And that's indicative of the bigger problem that Trump presents the media and why he's so bad for this race: He is the car-accident candidate. You know you shouldn't slow down to look but you know you will.
It's a virtual certainty that Trump's announcement will draw more attention -- particularly on social media sites like Facebook and Twitter -- than Jeb Bush's did Monday. Hell, it's possible that Trump's speech -- and the 30 plus minute off-the-cuff riff that followed it -- will be the single most attention-getting/buzz-creating event of the 2016 race to date.
As pure entertainment, it's hard to trump Trump because, as I mentioned above, he'll say just about anything. "Nobody builds walls better than me," he said at one point today. "I will never be in a bicycle race," he said at another. I could give you some context for those quotes except that there is no context. That's what makes Trump such great copy. That's what makes Trump so irresistible to write about and read about. It's also what makes Trump so dangerous to the political process. (Sidebar: I simply don't buy the idea that Trump's high-profile somehow brings a lot of new people to the political process and winds up being a sort-of good thing.)
A candidate with numbers like that is not the sort of candidate who commands live coverage on all the major cable networks when he announces for president. And yet, that's exactly what Trump got this morning. He's irresistible because he drives eyeballs and clicks -- and we live in a media world aware and incentivized more so than ever before by those metrics. We get Trump because, at some level deep down, we want Trump. And the media, at least in some sectors, is in the business of giving people what they want.
But attention doesn't equally credibility. Entertainment value doesn't equal electability. Being famous isn't the same thing as being respected. Sideshows are fun until they want to be the main attraction.
Donald Trump will never be president. He knows that. We know that. But his candidacy ensures that for the next several months (at least), he will suck the attention and oxygen away from the men and women who might be. That's great entertainment. But it's terrible for politics.