Over the summer, Trumpworld operatives, Republican Party oppo researchers, and GOP aides in Congress have all gleefully celebrated planting unflattering stories about Joe Biden, Bernie Sanders, and Kamala Harris. But no one seems to have landed a lasting blow on Elizabeth Warren.

The earliest days of the Massachusetts senator’s presidential campaign provided ample fodder for Republicans. After an attempt to blunt President Donald Trump’s racist taunts about her Native American heritage by presenting the results of a DNA test fell flat, GOP operatives had a field day, and figured they’d feast off that misstep for some time.

But Warren has recovered from that initial stumble, and steadily gained ground in the Democratic primary. And now Republicans are wondering why there is so little critical coverage of the senator and why the stories out there are making next to no dent.

“We all push out the bad Warren stories but they don’t go very far,” one Republican strategist said.

The frustration Republicans are beginning to feel about Warren’s non-stick nature was picked up repeatedly in interviews with 10 Republicans, including Trump campaign and White House officials, associates of the president, and other GOP operatives with knowledge of the situation. These sources stressed that the anti-Warren effort within GOP circles hadn’t fallen off since the DNA snafu. Indeed, everyone from officials on Trump’s 2020 re-election campaign, to the Republican National Committee, to a select group of opposition researchers have been sifting through her record in search of vulnerabilities. But with few punches landing, the worry is that Trump may have already taken his best shot, and that Warren will end up looking increasingly formidable for having bounced back.

“Sure the Republican base will ultimately loathe Warren, but she doesn’t inspire the same kind of historic vitriol that Hillary Clinton did,” a separate Republican strategist said. “That, combined with fact that SCOTUS isn’t on the line as it was in ’16, and remembering that Trump needed the perfect inside straight to barely win last time, and any Democrat is going to be tough to beat, Warren included.”

Within Trumpworld and the president’s re-election effort, there has been a dramatic shift in how Warren is talked about now, versus how she was discussed as a potential nominee a year ago. Shortly after the release of the DNA test results last year, Trump—along with numerous administration officials, campaign aides, and outside allies—would routinely mock the senator, and privately insist that defeating her in a 2020 matchup would be a cakewalk. Warren was at one point regarded as the preferred candidate for Trump to face off against in the general election.

A year later, they’re not laughing her off. In recent months, senior Trump campaign officials have increasingly discussed Warren as a growing threat, in large part because of the enthusiasm they believe she can inspire on the progressive left, and her improving poll numbers in the primary, two knowledgeable sources say. The president of the United States appears to be taking her candidacy more seriously, as well.

According to three people who have spoken to Trump about Warren over the past two months, the president has specifically highlighted what he views as her surprising political and populist talents during the Democratic primary, and has told multiple advisers and associates that he hears she could be “tougher” in a general election than many initially expected. One of these sources said Trump asked the room if they thought Warren was a “fighter.”

“ Bernie just screams and shakes his fist but she’s very strategic. ” — Republican Senate aide

The Warren campaign declined to comment for this piece. But multiple Republicans argued that while Sanders received his fair share of attacks by Democrats and critical coverage both in 2016 and in 2020, Warren has largely gone unscathed. And they view her ability to campaign without taking too much incoming fire as a testament to her skill.

“Bernie just screams and shakes his fist but she’s very strategic,” one Republican Senate aide said about Warren.

But the aide also argued that Warren was unlikely to skate by forever. “All the attacks that you’re seeing about Bernie would apply [in the general],” the aide said, “it would be a nasty campaign.” And while there is more admiration for Warren’s political acumen now, not all GOP strategists believe the primary has been a boon for her.

“She will have an energized base. Biden would not,” said Barry Bennett, a former senior adviser to the 2016 Trump campaign. “But her base is her eventual undoing. To accumulate that base, she had to take hard-left positions that are wildly unpopular with swing voters.”

As Bennett noted, the lines of attack that Republicans would take against Warren extend beyond allegations that she embellished her heritage and into accusations that she’s a radical. But there are some other biographical vulnerabilities too.

A Washington Post article spotlighted a discrepancy in the number of legal cases Warren’s campaign released on its website versus the number she appeared to be involved with in some capacity. Separately, CNN’s investigative KFile team looked into Warren’s role as a law professor who, the story notes, “criticized the overabundance of government regulations, calling them ‘a tax,’ and spoke to conservative legal groups like the Federalist Society and the Manhattan Institute.”

But what has surprised Republicans is how few and far between these stories have been, and how irregularly they’ve been picked up by both mainstream and conservative publications.

Looking to identify possible reasons for the downtick, one Republican suggested that Warren’s rapid rollout of policy plans could simply be moving too quickly for conservative think tanks to keep up. Those outfits would typically analyze the details of candidates’ plans and offer a counter analysis. With the frequency that Warren releases her proposals, the source said it could be hard for think tanks to look at each one with a fine-tooth comb.

Still, nearly all Republicans interviewed said they were confident attacks will ramp up in the coming weeks, as the Democratic primary field winnows and Warren receives fresh attention as one of the most likely challengers to former Vice President Biden. The Republican group America Rising, for example, has been tracking Warren since 2017 and has shown no signs of narrowing its oppo research file.

“If we’re having these same conversations in eight weeks, that’s a very different conversation,” said Doug Heye, a Republican strategist, who chalked up the perceived lack of attacks as largely overblown.

“If you throw those punches but no one is watching the fight, it doesn’t particularly matter.”

—With additional reporting by Sam Stein