Paul Waldman comments on Rubio’s predicament:

Marco Rubio is in serious trouble, so he’s now attacking Donald Trump, something he hasn’t been as eager to do before. While it may produce a return slap from the Republican front-runner, it probably won’t be enough to shift the discussion around Rubio, who is now learning a very hard lesson: Live by the media’s favor, die by the media’s disfavor.

One of the curious things about this election cycle is how relentlessly many media outlets and pundits have promoted Rubio with so little effect. It is quite possible that the overt and undeniable pro-Rubio bias in election coverage has helped to sour many voters on him and make them more suspicious of him than they might otherwise be. The desire to hype Rubio as the “real” front-runner or most likely nominee has been persistent for months despite the lack of evidence to support these claims, but until the Iowa caucuses it yielded no benefits for Rubio. In fact, it created increasingly unrealistic expectations of what he should be able to do, which made the shortcomings of his underwhelming campaign more glaring than they already were. The glee with which his third-place finish in Iowa was greeted in the media (and not just movement conservative media) was impossible to miss, but that ended up making Rubio’s bad debate and his predictably poor showing in New Hampshire seem even worse than they were. The constant boosterism and the endless string of media-created “moments” that Rubio was supposedly having throughout the last year helped obscure the candidate’s flaws and widened the gap between what everyone expected him to be able to do and what he could do.

The trouble with being a media-driven candidate is that it makes the candidate heavily dependent on continued positive coverage, and as soon as that coverage changes and the candidate suddenly faces intense scrutiny for the first time it magnifies every setback to an extraordinary degree. Rubio had the particular misfortune to stumble during a debate, which was supposed to be one of his strengths, and to make a mistake that had nothing to do with policy and everything to do with performance. Rubio could spout nonsense about the nuclear deal for days and never be called on it, but screwing up in a back-and-forth with a rival on live television is fatal for such a candidate. He has relied on positive coverage to build him up into being perceived as a plausible nominee, and the coverage has dramatically and maybe irreversibly changed.

Now that Rubio has been subjected to widespread ridicule instead of fawning admiration, he is left with nothing but a campaign strategy that can’t and won’t work. The core of that strategy all along was that everything would go perfectly for Rubio and all of his rivals would screw up or fade away in a timely fashion, and to make that happen it was essential that Rubio didn’t endure any negative or embarrassing coverage of the sort that he has had to endure for the last several days. However, a plan that doesn’t account for inevitable setbacks and adversity is not much of a plan at all, and no amount of positive spin in the media is going to change that.