Let's be honest. Trump is really a third-party candidate

Carlo Allegri | Reuters

Republican presidential nominee Donald Trump appears at a campaign rally in Warren, Michigan October 31 2016.

In these final days of the election, most of the major polls show support is waning for Libertarian Party presidential nominee Gary Johnson and Green Party nominee Jill Stein.

No surprise, right? Haven't we all been told since grade school that third party candidates never really have a chance in a national election?

My own 13-year-old daughter actually just read this exact same conventional wisdom in her social studies textbook. And she came home very angry about it because she thought it was patently unfair not to give every candidate a chance. But, it turns out the experts, textbook writers, and everyone else has it wrong this time. Because this time, there is a third party candidate with a chance to win. His name is Donald Trump.

OK, technically, Trump is the Republican nominee. But for all intents and purposes, Trump has been running a campaign in direct opposition to both the Democratic Party establishment and the Republican Party leaders. But thanks to the surge in new GOP primary voters earlier this year, Trump was able to win the Republican nomination in spite of how deeply he's rankled everyone from Senator John McCain, to House Speaker Paul Ryan, to 2012 GOP presidential nominee Mitt Romney.

And, since the Republican Party powers did not use whatever powers they had to stop him from officially getting the nomination at the GOP convention in Cleveland, Trump has been able to get the best of both worlds. He continues to promote a message and policies that often fly in the face of Republican orthodoxy, but still gets to have that coveted "R" next to his name on the ballot in all those red states where running as anything other than a Republican is political suicide.

In the battleground states, party affiliation doesn't matter as much. That's what essentially makes them swing states in the first place. And every time the Republican establishment joins with their Democratic Party counterparts in bashing Trump, it doesn't wound him in those states as much as it does in the states that are deep blue and red, respectively.

Every time Hillary Clinton insists Trump is a presidential candidate like no one ever before, she also helps in Trump's efforts to paint himself as essentially a third party "different" candidate who actually has a chance to win.

It's almost impossible to underestimate how crucial that is. Because we all know that the Achilles Heel for every third-party candidate from Ross Perot to Ralph Nader is the fact that almost every voter knows they simply don't have any realistic chance to win. And as principled as we all think we are when it comes to voting, none of us like to throw away our vote on a sure loser. And even if the most pessimistic poll numbers about Trump are correct, he still has a much better chance to win this election than any third-party candidate in more than 100 years.

Third-party candidates also don't usually have much of a chance because the majority of voters just haven't had the stomach for the kind of upheaval such a major change would bring to a government used to either Democratic or Republican rule for so long. But appetites are clearly changing. Both the Republican Democratic primary season brought strong pro-upheaval movements into the spotlight. Trump rode his to the nomination, while Senator Bernie Sanders took his movement all the way to the third closest presidential primary result for a major party since the primary process began. The hunger for change is stronger than ever this year, and it is decidedly bipartisan.

All of this has allowed Trump to package himself as a viable candidate despite all the conventional wisdom and history headwinds. Because he's said so many things the leaders of both parties have uniformly condemned, he can go to the battleground states and make a strong case for himself as a change candidate the entrenched powers both don't like. That's especially true in the crucial state of Ohio, where the Republican Governor John Kasich just publicly said he didn't vote for Trump. But because he still has the official Republican nomination, he can go to the solidly red states like Utah where he can say he's the Republican who can actually win this election as opposed to local favorite son Evan McMullin. And because he is just as unusual and controversial as the quirkiest third party candidate, he has neutralized much of the Democrats' usual playbook against conventional Republicans. He's the un-Republican.

It's this third party-like essence of Trump's campaign that's kept him afloat through his many verbal stumbles, missed debate opportunities, and even the "Access Hollywood" tape mess. It's the only way anyone could survive what Trump has endured and inflicted upon himself over the past year. And as more and more independents gravitate to his third party candidate-like vibe, it might take him right to the Oval Office.

Commentary by Jake Novak, CNBC.com senior columnist. Follow him on Twitter @jakejakeny.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.