Update: NBC News and the Wall Street Journal are out with a new national poll showing Trump falling behind Ted Cruz by two points. The poll also shows him trailing both Cruz and Marco Rubio by 16 points (!) in head-to-head matchups -- bearing out the point I make below.

That point being: Once this race reduces to two candidates, Trump is no longer the front-runner. The real question is how quickly that happens, and whether he's amassed too many delegates already.

So, a lot of The Fix's recent analysis is trending in the direction of a Donald Trump GOP presidential nomination. It's looking more and more likely, even as many of us -- not just The Fix, but many people in general -- still can't quite believe it's possible. Well, it is.

But it's hardly inevitable. And in fact, there's still a good case to be made that Trump has a ceiling in this race -- and that, if and when we get down to two candidates, Trump could hit that ceiling and lose.

The case in point for this argument is the interactive below, based on polling of Saturday's South Carolina GOP primary from Democratic firm Public Policy Polling. The interactive, from the voting reform group FairVote, shows how the South Carolina contest breaks down if it had ranked-choice voting.

Trump leads Marco Rubio and Ted Cruz each by 17 points in the current six-candidate race. If you eliminate the other three candidates, though, Trump's lead over Rubio drops to 12 points. And if you then take Cruz out, it's a virtual tie: Trump 46, Rubio 45.

A tie ballgame isn't "Trump loses," of course, but it does diminish his chances significantly. In other words, there is still an argument to be made that the thinning of the field could help the GOP rally around a Trump alternative and defeat him.

But here's the catch: That could all simply happen too late, and the clock is very much ticking -- even as only two states have voted. In fact, in two weeks time, about one-third of states will have already voted, which could put Trump in very strong position in the delegate race before the field drops to two candidates. And by this time next month, three-fifths of states will have voted.

We still have three GOP establishment candidates in the race, Ben Carson and Ted Cruz. And while you could make a case that Jeb Bush's, John Kasich's and Ben Carson's days are numbered, Cruz isn't going anywhere for a while. As I've noted before, the "SEC Primary" on March 1 could be good for Cruz, as could the Southern states that follow. And in a three-candidate race, we would reinforce, Trump's lead is still double digits.

But if you are sitting there, apoplectic about the prospect of Donald Trump being the GOP nominee in 2016, it's at least a little bit of hope.

Either that, or it's really a reality check that the GOP establishment is grasping at straws at this point.