"The maddening thing about this is that Trump’s plan does have some good new ideas, but for some reason they weren’t featured prominently enough in his speech or in the official campaign release."

And now, after a year's worth of skilled marketing that successfully separated him from that losing GOP national brand, Trump has waltzed right back into an electoral/ideological trap by delivering a speech and a plan that mostly looks like it could have been authored by Mitt Romney, John McCain and George W. Bush. By leading and dominating his speech and plan with calls for tax and regulatory cuts, Trump sounded like every Republican candidate for president since 1980. Make no mistake, more tax and regulatory cuts are exactly what this country needs. But you have to be very politically tone deaf not to notice that promoting those policies haven't really helped any Republican win the White House since 1988.

The maddening thing about this is that Trump's plan does have some good new ideas, but for some reason they weren't featured prominently enough in his speech or in the official campaign release. Chief among those good new ideas is Trump's call to end the carried interest tax loophole. That's the rule that allows Wall Street investment-fund partners to treat their income as capital gains and pay the much lower tax rates on them. Some Republicans have favored eliminating this loophole before, but the news media has either not been aware of them or deliberately ignored them.

So, imagine the impact on that media and the voters if Trump had used the unprecedented media attention on his Detroit speech and began that address with a longer version of the anti-Wall Street tirades he's delivered on the campaign trail from time to time. Imagine if, during that tirade, he then explained his call to eliminate the carried interest break well before he talked about any tax breaks for anyone. That would have been the right way to go for a man who, before Monday, had successfully cast himself as the first anti-Wall Street/big business Republican presidential candidate since Teddy Roosevelt. As we say in the news business: "He buried the lead!" Trump did talk about how international trade deals have hurt blue collar workers, but he failed to couple that with the even more persuasive flip-side discussion about how they've greatly benefited Wall Street investors. His speech should have been dominated by those kinds of comparisons. Instead, he threw most of it away on the usual GOP mantra of lower and simplified tax rates and brackets.

And there were other missed opportunities. By delivering this speech in Detroit, Trump could have recast himself as a Jack Kemp-style Republican who understands that income and corporate tax breaks are not how you start a conversation with poor minority voters stuck in Democratic Party-dominated urban regions where the only constant is neglect. Yes, Trump did talk very briefly about how the Democratic Party has presided over Detroit's devastation, but he never adequately explained how his tax-cutting plan would help.

Trump could have used his identity as the consummate New Yorker to talk about how Kemp's regulation and tax–relaxed "enterprise zones" helped turn around areas like Harlem. Instead, there was no mention of enterprise zones at all. And Trump failed to include any personal stories at all in his speech and those kinds of narratives are crucial if you want to find some way to make cold economic data and plans resonate with the voters. He did talk briefly about how, as a New Yorker, he saw then-Senator Hillary Clinton's failed economic promises in the state. But that was too little and too late.

You have to ask what the point was of Trump using the national stage in Detroit to deliver an address that seemed to really be directed at traditional Republicans only. Yes, Trump probably wants to bring more of them back into the fold in the wake of so many GOP defections to Hillary Clinton lately. But even if Trump could get them all back, it still wouldn't be enough. His best chance to win has always been the risky-but-necessary creation of a new base of voters. And that's even though that strategy has predictably lost him the support of some GOP base voters and Republican elected leaders.

Almost every news media pundit is bashing the details of Trump's plan based on their same old left-leaning economic theories and dogma about tax cuts. Like every liberal critic since 1980, they're insisting Trump's plan will blow up the debt, the same debt they don't ever seem to care about when it's being blown up by out-of-control spending.

At the same time, they're giving Trump a bit of begrudging praise for remaining reserved during the address, enduring the multiple heckling incidents, and sticking to the teleprompter. In other words, Trump is getting bashed for presenting a plan that sounds like it came from Mitt Romney while being praised for acting a little more like Mitt Romney. Big deal. It's inexcusable for the Trump campaign and Trump himself not to recognize that the key to his success has been that he doesn't look, sound, or act like any major presidential candidate of the past. What Trump did in Detroit was not what he's been doing to win so far, and it's not the way to win now.

The news media doesn't know this and never will, but that speech was much more lethal to the Trump campaign than any of his controversial comments over the past year.



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



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

