The establishment is scrambling.  Conservative backers of Ted Cruz are stunned.  Donald Trump's impressive victory in Nevada has knocked both back on their heels.  It should.  Against two major candidates – Cruz and Rubio – and lesser candidates, Trump racked up 46% of the vote.  Trump – and the reaction to him – revved up turnout levels that more than doubled the turnout in the 2012 GOP Nevada presidential caucuses.

Before Trump backers pop the corks on their favorite champagne, however, its needs to be underscored that the fight for the Republican nomination isn't over – yet.  Next week's Super Tuesday is a watershed.  Yes, Trump has won three out of the four initial contests without a close second finisher.  He barely lost Iowa.  He's racked up more votes to date than Mitt Romney had (420,000 votes for Trump versus 311,000 for Romney).  But Trump's drive to the nomination could be slowed on March 1 – could, that is, not will.

The devil is always in the details.  Super Tuesday features 12 GOP state contests (and American Samoa).  These are proportional contests, with the exception of three states.  Among the proportional contests, most have minimum vote-total thresholds that candidates have to reach to receive a proportional share of delegates.  Trump will have zero difficulty achieving the minimums.  Rubio and Cruz, on the other hand, may struggle to do so in some contests.    

Mark well: the process is about how raw vote totals translate into delegates.  It's about achieving 1,237 delegates to win the nomination.  Trump's Nevada win garnered 14 delegates.  That's strong, but another 16 delegates were distributed to Rubio, Cruz, and also-rans.

To win the nomination outright, Trump needs to accomplish what he did in Nevada – over and over again.  That's snagging 45% of the vote in upcoming contests in order to collect the requisite number of delegates to avoid a deadlocked convention. 

Most of the Super Tuesday trials feature high-end thresholds, which, if attained by a candidate, deliver at-large votes to the winner.  But the thresholds are 50% in most contests.  Trump has yet to achieve 50% of the vote in any of the February contests.  (Note that the 50% threshold applies to Texas.  Ted Cruz isn't likely to win 50% of the vote there, even if he wins the contest, which isn't a given.)   

The upshot is that a "win" for Trump on Super Tuesday is hitting that 45% vote-total threshold, thereby collecting enough delegates to end talk of a deadlocked convention. 

Could Trump roll up Super Tuesday and position himself as the GOP nominee?  Yes, indeed.  Perceptions and what George H.W. Bush called the "Big Mo" may play powerfully for Trump in the lead-up to March 1.

The perception – in line with the reality – is that Trump, with a relatively modest financial investment and commanding presence, is mobilizing voters from critical cohorts, thereby gaining strong plurality victories against formidable opponents and against a once crowded field.

The Big Mo – momentum – comes with a sense of inevitability.  Everybody – and that includes voters – loves winners.  Trump winning means a lot of voters are poised to jump on his bandwagon.  That's new voters showing up at the polls and switchers, who no longer see Cruz or Rubio as viable.

Come Super Tuesday, a combined surge of new pro-Trump voters and switchers would not only boost Trump's totals, but depress contest results for Rubio and Cruz.  Most of the Super Tuesday elections are "open," meaning not restricted to GOP voters, which favors Trump.  Deflated results for Rubio and Cruz likely sound their campaigns' death knells (even if they limp on to subsequent races).  Most contributors tend not to throw good money after bad, so Cruz and Rubio showing poorly would translate into the money spigots starting to close for both.

On the flip-side, if Trump fails to hit the aforementioned vote total average percentage, and if either Rubio or Cruz – or both – finds traction, then the likelihood of a deadlocked convention increases.  Short of a Trump implosion, there's really not a realistic path to the nomination – outright – for Rubio or Cruz.     

Unknown factors could come into play before next Tuesday that boost Rubio's and Cruz's fortunes, but they had better hurry up and get here.  If – and that's a big if at this point – Trump falls short next Tuesday, then a deadlocked convention remains in play, with the Republican nomination undecided until July in Cleveland.    

As of this writing, the trend and the tea leaves favor Trump on Super Tuesday.  Winning big for Trump next week will effectively end the fight for the GOP presidential nomination.  At that point, the Republican establishment and Cruz conservatives will need to come to grips with that reality and how they'll accommodate it – or not.