There's a reason Donald Trump has pulled into a tie or even into the lead in so many new national and battleground state polls: Hillary Clinton and her campaign are making mistakes. And no mistake is more obvious right now than Clinton's foolish decision to invite Dallas Mavericks owner and "Shark Tank" star Mark Cuban to the first presidential debate.

It's a mistake that shows just how unaware the Clinton camp is of how many voters see Clinton and her connections to rich and powerful elites and celebrities. Sure, Cuban's brash style and harsh attacks on Trump in recent weeks have grabbed headlines and burned up social media. But do they really fire up swing voters? Is a billionaire really the kind of person Clinton wants people to think she's fighting for? Or do they think Cuban's presence in the audience so close to the podium will somehow rattle a guy like Trump who's faced incessant heckling for 15 months on the campaign trail?

The answer to all the above questions is of course, "no." But the Clinton campaign's inability to see this problem in this one case is similar to its inability to see that, when one establishment figure after another endorses Clinton, it backfires in Trump's favor as he continues to make his case as a true anti-establishment candidate of change.

There was a brief chance that Trump might fumble this gift from the Clinton side when he openly tweeted about perhaps bringing former Bill Clinton mistress Gennifer Flowers to sit by Cuban's side. But that turned out to be just bluster, and now Cuban will have to sit quietly among the host venue Hofstra University students and anonymous donors as the debate unfolds.

Don't be surprised if Trump even points out Cuban's presence as proof of Clinton's too cozy relationship with the super rich and famous.

That front row seat she's giving Cuban is a missed opportunity. Clinton keeps telling us about how Trump has screwed many of his small business partners and even construction workers for years and years. Her surrogates have also accused Trump of sexism and sexist practices at work. Couldn't her campaign find one of these supposedly aggrieved people to sit in that front row seat?

Clinton's lead in the polls has been eroding quickly and Clinton supporters have blamed everything from the news media to sexism. But this Cuban invitation is a prime example of why Team Clinton needs to take a good hard look at itself – not the media or anyone else.