A group of loosely affiliated Democratic operatives have been in discussions about putting together an effort to attack Sen. Bernie Sanders (I-VT) should he end up winning next week’s Iowa caucus and, potentially, the New Hampshire primary a week later.

The talks, which two sources described to The Daily Beast, are in their nascent stages, and have already hit a snag. Big money Democrats have shown reluctance at funding such an effort, which could consist of ads attacking Sanders, and institutions associated with Democratic politics have largely shied away from being part of any campaign that goes after the senator, either out of fear over the backlash or growing acceptance at the prospect of him becoming the party’s nominee.

“It’s not any one group of people” trying to build the anti-Sanders effort, said one of the Democratic sources. “It is a loose network of people who think he would be very problematic as a nominee. There is, at this stage, calls to, and conversations with, donors and organizations that might support such an effort. But as far as I can tell, nobody has found sufficient financial support to get it off the ground.”

The conversations have been driven by fear that Sanders could all but wrap up the nomination early in the campaign without having faced much pushback. Whereas in 2016, Sanders came under a barrage of attacks from Hillary Clinton over his voting record on guns and—more opaquely—the lack of diversity in his political coalition, the senator, who has significantly broadened that coalition since his last bid, has been relatively unchallenged this go around.

According to FEC records, the sum total of reported independent expenditures opposing Sanders—directly and by name—was just $32.72 as of Monday. And that was spent by Club for Growth, a conservative group that has also run digital ads that seem designed to actually boost Sanders among liberals and which supplemented those spots with a TV ad on Monday.

That may very well change in the coming days. The organization Democratic Majority for Israel, which is run by pollster Mark Mellman, is buying tens of thousands of dollars in airtime in Iowa, according to documents filed with the Federal Communications Commission on Monday.

Neither Mellman nor his organization responded to requests for comment, but those FCC filings suggest they will align more with the party’s moderate wing. The group’s ads, it told the FCC, will focus on “electability in the General Election of potential Democratic nominee”—a common charged lobbied against the Vermonter.

DMFI PAC, the group’s political arm, reported paying $57,750 for airtime on Cedar Rapids ABC affiliate KCRG from Wednesday though caucus day, and another $11,200 for spots on a host of DirecTV cable programs.

It’s not clear whether the group’s ad, which does not appear to have been posted online yet, will mention Sanders or any other candidate by name. But DMFI has previously gone after Sanders over anti-Semitic sentiments expressed by some of his surrogates, such as former Women’s March co-chair Linda Sarsour.

There are also signs that competing campaigns may be getting closer to going after Sanders as well.

Unite the Country, a high-dollar super PAC supporting former Vice President Joe Biden, has thus far opted to keep its messaging positive, promoting Biden rather than attacking any of his opponents. But a POLITICO report on Sunday offered a suggestion that the PAC may get more aggressive after the Iowa caucus.

“We have no plans and haven’t discussed it, but as we’ve said from the beginning, we don’t believe in unilateral disarmament,” a source familiar with Unite the Country’s plans told The Daily Beast.

Even members of Biden’s official campaign suggest that a sharper contrast may be drawn between the two candidates soon.

“One is a socialist. One is not,” said Dick Harpootlian, the former South Carolina state party chair and a Biden bundler. (A previous version of this article had stated that Harpootlian was a member of Biden’s national finance committee, as he told The Daily Beast. The campaign disputes that characterization.) “If the Democratic Party believes nominating a socialist is the way to win in November, they need to start drug testing at the national committee.”

“If it were up to me, I would be a little more aggressive,” said Harpootlian, addressing a question about post-Iowa posturing.

For Sanders’ campaign, the threat of attack is an implicit recognition of the senator’s success, and proof that his outsider appeal is working.

“Let’s be clear: our growing support results from working-class Americans from diverse backgrounds demanding an agenda that transforms our country,” said Faiz Shakir, Sanders’ campaign manager. “All Democrats should be ecstatic to witness this movement attracting new supporters. To win seats up and down the ballot, we need to generate excitement and enthusiasm that drives a huge voter turnout. Bernie Sanders has demonstrated over the course of this primary that this campaign is able to do that–and that’s why Donald Trump is nervous.”

In certain circles, however, there is confusion and fear that the nomination process has gotten to this juncture with little pushback against Sanders at all. Reasons for that vary. But among operatives on competing campaigns, the main explanation is that few, if any, saw utility in going after the senator at all.

Early in the campaign, many campaigns took concrete steps to court Sanders’ voters by embracing his policy portfolios on health care, the environment, and other fronts. The assumption that Sanders’ coalition was limited enough that he couldn’t outright secure the nomination persisted through the summer, when Sen. Elizabeth Warren (D-MA) was surging, and became even more pronounced after Sanders suffered a heart attack in October.

Former South Bend Mayor Pete Buttigieg, for one, took to attacking Warren on her hesitance, for months, to outline how she would pay for her Medicare for All plan. But Sanders, his critics bemoan, has not faced the same scrutiny, despite being the primary advocate of Medicare for All.

The hands-off approach was evident in the debates as well, where Sanders remained generally untouched by several of the leading contenders. Indeed, during much of the primary, multiple campaigns told The Daily Beast that his steady second-place standing was not considered to pose as immediate of a threat as did other frontrunners. Some Democratic officials also conceded they had been reluctant to go public with their criticisms of Sanders for fear that he would frame those as the party establishment trying to undermine his campaign, a charge that might potentially depress his voters by the time the general election came around.

Over the past several weeks, however, the landscape has begun to change, with Biden, Warren, and Buttigieg all taking fresh shots at Sanders over various issues. Clinton herself expressed public reluctance about supporting Sanders—who she said “nobody likes” in a recent interview—should he win the party’s nominee against Trump, before saying she’d back whoever won the nomination.

Biden and Sanders have gone after each other on Social Security, with Sanders correctly noting that Biden previously called for reductions to the program in the Senate, and the former VP accusing his opponent of muddying his record. Warren went public recalling a conversation she had with Sanders in which she said the senator expressed his belief that a woman could not beat Donald Trump—which Sanders denied multiple times.

And on Saturday, Buttigieg sent a fundraising email titled, “Bernie Sanders could be the nominee.” The post goes on to say that “Bernie Sanders is raising tons of money, he’s surging in the polls, and he has dark money groups attacking his competitors. If things stay steady until the Iowa Caucuses in nine days, Bernie Sanders could be the nominee of our party.”

Among some campaigns, there is a growing fear that the pushback—mild as it has been so far—has come too late; that Sanders’ crest in the polls has come at the perfect time. That’s caused angst in some quarters. But in others, many Democrats have grown comfortable with the prospect that the senator could end up being the nominee, believing that the asymmetrical political coalition that he puts together, along with the fundraising prowess that he possesses, would make him a strong candidate against Trump.

“He is not my first choice,” said Rufus Gifford, a prominent Democratic fundraiser who supports Biden. “And wouldn’t be my second. But I will be knocking on doors and raising money for him if he is the nominee.”