Washington (CNN) Elizabeth Warren's DNA test identifying her distant Native American ancestry is at its root a first stab at a question all 2020 Democratic hopefuls must answer: How do they run against a foe as menacing as Donald Trump?

It is a mark of how the President has dragged campaign politics into a surreal era that what was seen as a de-facto declaration of a coming White House bid by a major rival involved an investigation into her own genetic make-up.

The President has long mocked Warren for claiming she has a Native American connection and said he would love to confront her about it in a presidential debate. He showed Tuesday he is relishing an early 2020 showdown with Warren, lampooning her move in a withering tweet.

"Pocahontas (the bad version), sometimes referred to as Elizabeth Warren, is getting slammed. She took a bogus DNA test and it showed that she may be 1/1024, far less than the average American. Now Cherokee Nation denies her, 'DNA test is useless.' Even they don't want her. Phony!" Trump tweeted, later calling on Warren to "apologize for perpetrating this fraud."

In a video accompanying the results of her DNA testing, the Massachusetts Democrat said she is not enrolled in any tribe but that her "family history is my family history.

"This isn't just about casual racism, war whoops, tomahawk chops ... Trump can say whatever he wants about me, but mocking Native Americans, or any group, in order to get at me, that's not what America stands for," she said.

In what could be a preview of things to come, the President immediately dismissed Warren's attempt to choose her own narrative.

"One one-thousandth?" Trump later asked reporters Monday, quickly spotting the most damaging potential of Warren's DNA result -- the finding first reported by The Boston Globe that she is between 1/32 and 1/1024th Native American.

Trump's mockery encapsulates the conundrum facing Democrats as the 2020 campaign kicks into gear, even before the 2018 midterm race wraps up in 21 days.

As a supposedly golden generation of Republican candidates and Hillary Clinton discovered in 2016, Trump is dangerous because he lacks shame. There's no level to which he will not stoop for political gain. When truth and evidence -- or a DNA test, branded "junk science" by his counselor Kellyanne Conway on Monday -- get in the way, he will pounce.

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Warren released a sleek, nominating convention-style biographical video Monday, complete with her holding a beer and showing her in her native Oklahoma with her older brothers. It came across as an effort to prevent Trump from defining her and introducing herself to Americans on her own terms if she decides to run for president.

Perhaps it will draw the sting from Trump's attacks, just as President Barack Obama sought to defuse the then real-estate magnate's claims he was born abroad by producing his Hawaii long-form birth certificate.

But it probably won't. Trump, who craves enemies and invents them if they don't exist, is relishing Warren's decision to engage.

If the facts don't favor him, he will just invent a more useful political reality.

Warren's dilemma

Warren faced a difficult choice. She could have ignored Trump's taunts and stuck to her message about middle class pain in an economy rigged by the rich. But Trump was sure to come after her.

The President has already seized on GOP claims that Warren used or lied about her Native American heritage to win benefits for minorities in her academic career -- a charge her video says is false.

The issue also hits a sweet spot for the President because it offers an opening to skewer Democrats for a perceived obsession with racial identity and minorities that plays well with Trump's white voting base.

But by addressing her ancestry before a campaign, Warren is signaling she won't be "swiftboated" like another Massachusetts senator who ran for President, John Kerry, who never effectively stifled attacks on his Vietnam War record in 2004 by veterans supporting George W. Bush.

Her move, which will give her a brief moment in the spotlight ahead of a bloated Democratic field, is also an early sign to party activists that if they chose her to take on Trump, she will not hold back. In fact, she was already trolling the President on Monday in a manner that seems to have got under his skin before.

"I took this test and released the results for anyone who cares to see because I've got nothing to hide. What are YOU hiding, @realDonaldTrump? Release your tax returns -- or the Democratic-led House will do it for you soon enough. Tick-tock, Mr President." Warren tweeted.

I never expected my family's story to be used as a racist political joke, but I don't take any fight lying down. I want you to have the power to fight lies with the truth, so here's a new site for you to review every document for yourself. https://t.co/900SsAMNjb — Elizabeth Warren (@elizabethforma) October 15, 2018

But there are potential risks to her strategy.

By talking about the issue at all, she is allowing Trump to define the early campaign terrain -- a technique he used to fell GOP primary candidates like Jeb Bush, Marco Rubio and Chris Christie last time.

Democrats debate 2020 plan

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Warren's gambit coincides with an intensifying debate among Democrats about the best way to confront Trump in 2020.

The 2016 Democratic nominee was referring to the midterms, but she also effectively laid out a tonal pointer for 2020 Democratic candidates.

She said that her 2016 mantra, "when they go low, we go high," still stands, even though its effectiveness was questionable two years ago.

There are other approaches that could work. By 2020, Americans might be tired of the crash-and-burn rhetoric and exhausting daily twists of life under Trump and could embrace a quieter, more conventional choice.

Or maybe an issues-heavy campaign -- by someone such as Bernie Sanders, bristling with liberal policy solutions on health care, inequality and the environmental movement could be a good fit for the times. But moderation may not tap furious energy raging through the Democratic grassroots ahead of the midterms.

In a party electrified by opposition to Trump and embittered by losing a Supreme Court fight, there is plentiful fuel to feed a scorched earth campaign against the President.

Still, no one can tell whether an all out negative assault can work against the master of "going low," who stoked racial and societal divides to build a winning coalition from a fervent Republican base in 2016.

It could also end up hurting challengers as much as it wounds Trump. After all, Republican foes such as Rubio saw their brands dinged by joining Trump in the gutter in a way that clashed with their more moderate political persona.

Get it all out

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An aide to Warren told CNN's Manu Raju that the DNA test was part of an effort to release as much information as possible, including a decade of tax returns, and academic files as the senator weighs a 2020 run.

She got a mixed reaction from Democratic political professionals.

Jen Psaki, a former campaign aide and White House communications director for Obama, told CNN's Jake Tapper that Warren's calculus was "smart" though probably would not work entirely because Trump would respond.

"She is going to run for President clearly, she wants to clear the decks, she is going to do everything she can to do that ... then she wants to move forward," Psaki said.

One of Psaki's former colleagues, Jim Messina, who ran Obama's 2012 re-election campaign, worried that Warren's timing was off.

"Argue the substance all you want, but why 22 days before a crucial election where we MUST win house and senate to save America, why did @SenWarren have to do her announcement now? Why can't Dems ever stay focused???" Messina tweeted.

Joe Trippi, who ran Howard Dean's 2004 Democratic presidential effort said Warren had actually waited too long.

"I would have done this a year or two ago ... because they didn't do it, she had to (now)," he said.