Sen. Elizabeth Warren (D-Mass.) in Miami on Wednesday night. (Drew Angerer/Getty Images)

Sen. Elizabeth Warren (D-Mass.) was the big dog on Wednesday’s Democratic debate stage, and she did not disappoint. Her passion and hard-line progressive beliefs shone through like a beacon cutting through thick fog. But those same convictions that can help her win the nomination could sink her in the fight against President Trump.

Time and again Warren stood up for her ideals. Her message is that the powerful are ripping you off and holding you down, and that a fighter in the Oval Office will set things right. It doesn’t matter if the powerful are contributors to the Democratic Party, such as big tech executives, or executives at unpopular pharmaceutical executives. Warren is a modern-day Isaiah, pledging to make low every mountain and hill and exalt every valley.

This is red meat for the deep-blue left, and she delivers her lines with verve and vigor. You can see how the years of being a law professor have shaped her speaking style. If you’re angry at American capitalism and think Democrats have sold out ordinary folk almost as much as Republicans have, then Warren speaks with your voice and echoes your priorities.

Warren’s trouble is going to come with voters who aren’t of the true-blue, red-meat variety. Roughly half of the Democratic primary electorate calls itself moderate, and polls show she does quite poorly among this group. She said nothing on Wednesday that speaks to this group, nothing that reassured the Democrats who think the United States needs fixing but isn’t fundamentally broke. That’s Joe Biden’s territory, and Warren is not yet equipped to fight for these voters’ loyalty.

The passion that will attract progressives could wear thin with the less devoted. Warren spoke for only about nine minutes Wednesday night, and the long gaps between her interjections were filled mainly with less energetic language. That gave the viewer time to recharge after her heated statements. Her speaking time will go up in future debates as the number of candidates decreases, however, and if she is the nominee, she will be talking for more than an hour in the debates against Trump. Moderates and swing voters might find her intense populism off-putting when subjected to it in large doses.

Warren’s riskiest ploy is her enthusiastic endorsement of abolishing private health insurance. As former congressman John Delaney (D-Md.) pointed out, more than 100 million Americans receive their health insurance through private plans, whether provided by their employer or purchased on the individual market. There’s no indication that they are willing to give up those plans even if they would prefer to pay less and get better service from their insurer. Trump will make this a big issue in the fall, and many moderate Democrats would probably prefer to avoid giving him such a powerful weapon.

Warren also has a recurring problem with authenticity. Her closing statement included a brief biographical sketch that is a regular feature in her stump speech. She says: “By the time I graduated from high school, my family didn’t have the money for a college application, much less a chance for me to go to college. But I got my chance. It was a $50-a-semester commuter college. That was a little slice of government that created some opportunity for a girl. And it opened my life.” This simply isn’t true.

Warren actually went to a private college, George Washington University, on a debate scholarship. She attended GW, which cost much more than $50 a semester and is definitely not a commuter college, until her high school sweetheart proposed to her. She accepted, got married, dropped out of GW and followed him to Houston, where he worked for IBM. That was when she enrolled in her $50-a-semester commuter college, the University of Houston.

Her real story is actually pretty inspiring, so why the deception? Why imply that she couldn’t have gone to college without cheap public universities when it simply isn’t so? It’s not hard to see Trump ask, “If you can’t trust someone to tell the truth about herself, how can you trust her to tell the truth at all?” Despite Trump’s own weakness on this point, it’s not hard seeing that charge stick for Warren.

Warren hit all the right notes during the debate to secure her position in the top tier. But if she actually wants to sit in the Oval Office, she’s going to have to make some adjustments pretty soon.

Read more:

Stephen Stromberg: Democrats can do better than Warrenism

Jennifer Rubin: Warren’s fateful choice on health care is a gift to her opponents

Ed Rogers: Ranking the Democrats’ debate performances

Helaine Olen: Elizabeth Warren and the double standards for female leaders

Erik Wemple: Why not let the Democrats actually debate?