Dan McCarthy sums uplast night’s debate spectacle:

Was this the debate where Marco Rubio became the GOP frontrunner? Not really—Donald Trump and Ben Carson, neither of whom took any damage, still lead the pack, and there’s plenty of jostling among the others for the number three slot. Ted Cruz had about as good a night as Rubio. But the Florida senator certainly stands to gain the most from Jeb Bush’s ongoing implosion, and after a pitiful performance last night Bush looks about as forlorn as ever Rick Perry or Scott Walker did.

We saw again last night that Rubio is very lucky in his opponents, and Bush is one of the worst political performers of the last three cycles. For all his complaints about media bias against him, Rubio continues to be built up and hyped by journalists and pundits regardless of what happens. Provided that Rubio didn’t commit any unforced errors, the stage was set to declare him the winner and Bush the loser once it became conventional wisdom that Bush had to have a great debate. Rubio also benefited from facing some of the worst moderators of this or any other cycle, which allowed him to lash out at the very minimal media scrutiny he has received.

It’s true that Rubio put in a good performance overall, but then that is what one would expect from a candidate who is mostly known for what he says in speeches and debates and not for what he has done. Bush is a terrible candidate, but that isn’t really surprising when we remember that he has been out of office for almost a decade and hasn’t contested a truly competitive election in over fifteen years. While Rubio swatted away Bush’s attack on his absenteeism in the Senate effectively, it also doesn’t take much to counter an attack from someone as hapless as Bush. The fact that Rubio and Bush are quarreling with each other while leaving the leading candidates untouched is a reminder of how weak and divided the so-called “establishment” candidates are overall.

It is notable that the three Republican candidates that have been routinely described as “top-tier” have struggled as much as they have. Walker has already dropped out, Bush is flailing, and Rubio continues to muddle along with relatively little support or money. Rubio is presumed to be an “unusual front-runner” because he is currently doing the best of these three, but at this point there’s really no reason to believe that any of these “top-tier” candidates deserve to be viewed this way.