Noah Millman sums up the weaknesses of the Rubio campaign in response to a recent Douthat column:

But Rubio hasn’t been Kutuzov, retreating into Russia and waiting for winter, because he never held Russia. Lots of people bought into the idea that he was the “stealth” front-runner, but he was never anywhere near to having a commanding position – not even in his home state. He started out far behind his own rhetorical positioning, and has consistently and badly underperformed his own campaign’s goals in states that are absolutely key to his victory. He is exceptionally poorly positioned for the states that follow Super Tuesday [bold mine-DL] – and there’s no reason to believe that this position will improve if he doesn’t win any states on March 1st. It’s not just that he doesn’t have time to consolidate the non-Trump vote and win. It’s that he was never in a particularly good position to consolidate the non-Trump vote.

This is all entirely correct. Rubio was not (and now never will be) the front-runner. Besides the inherent flaws of a “wait, wait, wait” strategy in a contest designed to reward early winners, Rubio’s campaign has never been in control of its own destiny. He has always needed other candidates to fail and drop out on a specific schedule, and he needed voters to start rallying to him. If the other candidates don’t cooperate (as Kasich is refusing to do now), his strategy starts looking very shaky. When the voters refuse to cooperate as they have over the last three weeks, his strategy is revealed as the joke that some of us have long known it to be.

Rubio took a large, bad gamble in this campaign that he just had to wait out most of the field and then start winning after months of losing. No one had ever succeeded doing anything like this, and the plan made no sense because the rules were written specifically to prevent a candidate from dragging out the contest for as long as Rubio theoretically needed to drag it out. The military officer Rubio calls to mind is Baron Raglan with his ill-conceived, mostly disastrous operations in the Crimean War: begin with a bad strategy in a foolish campaign, and then execute it poorly.

Millman also explains why Rubio’s candidacy still doesn’t make much sense:

Of course, that’s completely unfair. Rubio had every right to run – and folks like Jeb Bush have nobody but themselves to blame for their losses. But so is the suggestion that the rest of the field should clear the way for Rubio, the obvious best candidate, to be the nominee. Because, among other things, he isn’t obviously the best candidate. To my mind, Kasich is clearly the best candidate to face off against Clinton (as well as the one who would make the best President). And if all you truly care about is winning, I’m really not sure anymore that Trump isn’t a better choice than Rubio.

It’s understandable that Rubio’s opponents see no need to help him, but they’re also refusing to bow out because Rubio isn’t the “manifestly superior” candidate that his boosters keep touting. When all is said and done, he will probably have fewer victories and fewer delegates than the candidates he is trying to push out of the race. Unless something changes dramatically in the next few days, it’s conceivable that he’ll have to drop out before either Cruz or Kasich. In that sense, it doesn’t really matter whether Rubio attacks Trump tonight or at the later debates, because he has repeatedly shown that he can’t win anywhere even when he does well in the debates.