Hillary Clinton’s VP pick: There’s really only one choice

Now that Hillary Clinton has essentially nailed down the Democratic presidential nomination, the growing focus is on who she'll choose as her running mate. And there's no other way to put it: This is probably the most important VP decision in the history of modern American elections. A wrong move here would negatively impact her election chances more than any other major party nominee in more than a century.

Let's face it, running mate choices haven't really made much of a difference in just about every presidential election. Does anyone really make their choices based on who's on the bottom of the ticket? Take the 2008 GOP nominee John McCain's choice of then-Governor Sarah Palin as his running mate. That was a decision almost all the conventional wisdom experts agree was a huge mistake... except it really wasn't. The truth is McCain would not have won no matter who he put on the ticket and he probably couldn't have done anything to make it significantly closer. The same was true for Mitt Romney's choice of Paul Ryan in 2012, John Kerry's decision to go with John Edwards in 2004, etc.

But this time, it's different. Because this time we have a major party candidate who has two rare problems to contend with as she begins the general election campaign. First, Clinton is struggling with monumentally high unfavorable ratings in the polls. Second, she's faced with a Democratic Party whose ideology has clearly passed her by (i.e., Bernie Sanders).

In a party that's suddenly become more about ideology than identity, Hillary Clinton seems to be offering gender identity as a draw and she needs something more. Democrats want to see a running mate choice that mirrors the new economic ideology of the party or they just won't enthusiastically back Clinton as much as her campaign needs them to in November.

"Any male voter who's going to make the candidate's gender a conscious or subconscious deciding factor in his choice is already won or lost in this election."

In normal election years, the ticket is 99.9999 percent about the presidential candidate, and the "rest" is about the VP candidate. But with both Clinton and Donald Trump facing such high unfavorable ratings (56 percent for Clinton and 59 percent for Trump, according to Real Clear Politics), their running mates really matter this year.

The many pundits who have been predicting and weighing Clinton's running mate options have it all wrong. Because most of them continue to name Housing and Urban Development Secretary and former San Antonio Mayor Julian Castro is the "obvious" best choice. They even believe that Trump's repeated comments about Latinos add to the potency of Castro's name and face on the ticket. But that thinking completely ignores the Clinton campaign's real problems (that I mentioned above). Castro does nothing to aid Clinton's need to gain acceptance from the now dominant progressive wing of the party. And while Castro's youth and good looks will positively distract many voters from Clinton's negatives, that distraction won't last long. To really keep the focus off of Clinton's negatives for a long time, the public needs a running mate it can really sink its teeth into. (Besides, if the Clinton camp doesn't already have the Latino vote as sewn up and energized as it could possibly be, then there's no hope for her in November anyway. )

Forget about a list of other names. There's really only one person that Clinton should choose in order to overcome those hurdles: Massachusetts Senator Elizabeth Warren.

Warren is arguably a more popular standard bearer for the progressives than Sanders. And because she's been such a recognizable figure in the ideological debate for several years now, she provides plenty of material for the news media, voters, and everyone else to discuss for weeks. Even Trump routinely acknowledges her, if only to demean her in a ferocity he usually reserves for those running against him, even though she's not running against him for anything yet. Warren has also been busy for weeks honing her own attacks on Trump that have become the toast of left wing social media. Warren is the ultimate surrogate for Clinton, giving her a chance to take a breather and allow someone more tenacious and savvy to join the back-and-forth online war that Trump has been winning for some time.

What about the inevitable question of whether it's wise for Hillary to choose another woman as her running mate? Won't that hurt her among undecided male voters? Not really. Any male voter who's going to make the candidate's gender a conscious or subconscious deciding factor in his choice is already won or lost in this election. Besides, in choosing Warren, the Clinton campaign can trot out a new twist on a catchy and snarky slogan and say: "Hillary needs a man for her vice president like a fish needs a bicycle!" (I know the Clinton campaign and social media team will like that one; they can send payment to me for that idea, care of CNBC).

But seriously, this running mate choice is about much more than a catchphrase. The wrong choice here could really doom Clinton's chances and essentially end her political career. If the Clinton team truly sees its situation for what it really is, Warren isn't just the best choice, she's the only choice.

Commentary by Jake Novak, supervising producer of "Power Lunch." Follow him on Twitter @jakejakeny.

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