Tennessee Senator and now-former Donald Trump Vice Presidential finalist Bob Corker made a bit of news on Wednesday when he withdrew his name from consideration and said that Trump's best choice for a running mate just might be his daughter, Ivanka.

Was Corker half-kidding? You'd have to ask Corker, but even he did add that choosing Ivanka "wouldn't pass muster." Corker is right that Trump really can't pick Ivanka as a running mate for vice president. But for all intents and purposes, she has been acting as a virtual partner on the campaign trail and it would benefit Trump immensely to increase her role and visibility even more. And it's not just because Ivanka is well-spoken and physically attractive. To understand why she is so crucial to the Trump campaign, it's important to first understand the role family members have always played in presidential campaigns.

The biggest reason the voters are usually subjected to endless pictures, videos, and stories about the candidates' wives and children is because they almost always help to humanize the candidate. Politicians are like movie stars, despite all their protestations to the contrary they really aren't "just like us." They operate under a different set of goals, a different set priorities, and as we found out this week as the Hillary Clinton email scandal investigation wrapped up, they pretty much have a different set of rules.

In Trump's case, he even sounds and looks different. He says things that politicians and non-politicians alike wouldn't say in public. And his "tan" and hair … well, you know. Trump presents the manifold challenge of having to relate to the public despite being a billionaire who looks and sounds very different from them. The first person campaign spin doctors would usually turn to in order to make a person like Trump more relatable to regular folks would be the candidate's wife. But Melania Trump might as well be another space alien in that department. As a stunning former fashion model she does add a nice Jackie Kennedy-like degree of chic and class, but that's something else entirely. A lot of male voters might wish they had a wife like Melania, and a lot of women voters may wish they looked and dressed like Melania, but she doesn't humanize Trump very much. Just like the politically incorrect things Trump says may relate to the way a lot of voters think, it's not the same as relating to the way they work, live and act. Trump needs to go elsewhere for that.

So that brings us back to Ivanka. As a regular on "The Apprentice" and a visible businesswoman/celebrity with her own clothing line, the American people were relatively familiar with her well before the Trump campaign launched. She, too, is fashion-model gorgeous, but she's also closer in age to millennials (which is now the single largest generational group in America), and she's a married mother too. Speaking of marriage, she happens to be married to an Orthodox Jewish man and she converted to Judaism before marrying him. Ivanka's adopted religion and full immersion into the observant Jewish lifestyle has been a strong counter argument to those who continue to accuse the Trump campaign of anti-Semitism.

And Ivanka isn't just being used for visual purposes, or so we're being led to believe. More and more stories are being "leaked" about the growing advisory role she's playing in the campaign, the most prominent of which being the story that she played a big hand in ousting former Trump Campaign Manager Corey Lewandowski last month.

But wait, there's more! In many ways, it's a lot better to have a daughter humanizing and making the candidate more palatable to the voters as compared to a spouse. Whenever a wife or a husband is trotted out as someone who really influences a candidate, that can be a bit of a double-edged sword. Sure we like to have our candidates interacting and showing decent behavior with their spouse, but then worries about being hen-pecked or dominated in the relationship arise. Those were the kinds of criticisms Bill Clinton suffered from during his presidency from those who thought Hillary had too much influence in the White House, a concern that's come full circle now that Bill has made some damaging missteps like his recent ill-advised private meeting with Attorney General Loretta Lynch in Phoenix.

Children get a little more of a pass, but not always. Jimmy Carter found that out the hard way in 1980 when, during his lone debate with Ronald Reagan, he talked about how he asked his then pre-teen daughter Amy how she felt about the threat of nuclear war. Carter was pilloried for seemingly consulting with a literal child about national security matters. But somehow, when the presidential candidate's adult child is perceived to be a strong influence for that candidate it seems to be OK. And with someone as generally popular and accomplished as Ivanka Trump, it seems more than OK.

And Ivanka gives Trump something Hillary Clinton just can't match. Bill Clinton has become almost as much of a liability than he is an asset as a candidate's spouse. Chelsea Clinton is not seen as individually accomplished as Ivanka and has been hit with criticism for apparent nepotism in securing some high-paying jobs. And Chelsea simply doesn't have that Ivanka-like chic. In fact, some Clinton campaign events featuring Chelsea have bombed, including a well-publicized event in Manhattan that originally was peddled out for $2,700 per person but generated such weak interest that tickets at the last minute went for as little as $50. Something tells me an event featuring Ivanka Trump wouldn't have that kind of trouble.

Donald Trump will have to choose someone else for his vice presidential running mate. But he'll be hard pressed to find someone with as many plusses as Ivanka, who generates positive attention to his campaign and – most importantly – takes a good degree of the "crazy" off of his general image. The good news for Trump is that, while both candidates on the presidential ticket rarely campaign together on the trail, he can bring Ivanka with him wherever he goes and make sure she continues to be right behind him directly in camera range at every rally and speech. Melania is always visible too, but for different and less politically valuable reasons.

You can expect Ivanka to be more than just a sight prop as the campaign gets closer to Election Day. She won't be the running mate but don't be surprised if she's mentioned seriously for a cabinet post or ambassadorship. There is virtually no downside in that kind of move.