I have been studying the GOP numbers very carefully. It is still early and many voters are still not focused but thus far developer Donald Trump remains in the lead in national, Iowa, and New Hampshire polls. I looked closely at my most recent national poll taken November 8 and 9 and Mr. Trump still has 31% support, 13 points ahead of his nearest challenger, Dr. Ben Carson. Following them are Florida Senator Marco Rubio with 8%, former Florida Governor Jeb Bush 7%, Texas Senator Ted Cruz 6%, former Hewlett Packard CEO Carly Fiorina 4%, and Ohio Governor John Kasich 3%.

Reports have persisted for months that the Republican Party establishment is flummoxed over how best to damage Mr. Trump and remove him from contention. More recently, mainstream pundits have been suggesting the previously unthinkable - i.e. that Mr. Trump can actually win the nomination. Thus far, the billionaire has defied everyone and all the rules. The more outrageous his utterances, the better he seems to do in the polls. Challengers seem to come and go, but he has stayed on top. Any candidate who has dared to trash talk the former reality show star has been trashed right back one hundredfold. Negative ads are up and running by SuperPACS devoted to either other candidates or simply to his demise - but all to no avail.

Donald Trump's show is still going on. As long as he produces outrage, he dominates the coverage. So how does anyone stop him from winning? The ultimate wisdom comes from none other than one of the vanquished candidates, Wisconsin Governor Scott Walker, who in delivering his campaign farewell, argued that the GOP field must be limited. There are simply too many candidates.

I think Mr. Walker spoke the truth and someone has to listen. Let's look at those Zogby Analytics Poll numbers again. Yes, Mr. Trump's numbers continue to be most impressive - but a lot less so when we consider that 56% prefer another candidate and 13% are still undecided. That means 69% of likely GOP primary and caucus likely voters do not choose Donald Trump. Thirty-one percent looms very large when no other candidate comes even close. But no other candidate can match Mr. Trump for saying "newsworthy" things or for grabbing the spotlight every single day. It might be a far different story if there were only a few candidates left in the race. And it seems that both the SuperPACS, conservative-leaning pundits, and fellow candidates would spend their time more constructively focusing less on Mr. Trump - he does not need more attention - and making a stronger case for limiting the number of candidates in the field.

So let me make the following proposal. Regardless of the poll numbers and the sincerity of his supporters, Dr. Carson should just leave. He is smart (as a neurosurgeon), he has a nice demeanor about him, and he prays well publicly. But he has not in any way shown any real talent as either a candidate or a leader of this nation. He has little depth on matters of government policy and gives all the appearances of making this whole thing up as he is going along. One down.

Former Governor Mike Huckabee and former Pennsylvania Senator Rick Santorum have had their place in the sun, made their credible challenges, and show neither the polling numbers nor the field operations to make the grades they have made in the past.

Former New York Governor George Pataki and South Carolina Senator Lindsey Graham are merely blips on the screen, struggling at 1% or less. It has been months now and they have not shown any capacity for growth, even to earn a spot before the larger debate audience.

Governor Chris Christie had his time in 2012 and chose not run. He has had several bright moments in the debates this year but he just isn't cutting it. He is young and can try again perhaps. That's a total of six candidate leaving the field down to more manageable seven.

Who should remain besides Mr. Trump - and why? Messrs. Rubio and Cruz are gaining in the polls and provide voters with credible options. They also represent different wings of the party. Messrs. Bush and Kasich have proven track records - one as Governor of Florida, the other as a leader in the House and as Governor of Ohio. They are the moderate candidates and are in the mix of polling either nationwide or in early states.

Mr. Paul represents the libertarian wing of the party, has creds among younger voters, and makes the debates more lively. And Mrs. Fiorina has been a star in all of the previous debates and, while fading in more recent polls, had made some gains early on.

It would be wise for CNN to only invite these seven candidates to the next debate on December 15 - then for the pressure to begin to reduce the total down to four by the January 16 pre-Iowa debate. With voters paying closer attention, now we will all get to see how strong Mr. Trump's support really is.