Days before the Iowa caucuses, a group of moderate Democrats is making a final attempt to stop a surging Bernie Sanders with warnings about the “politically toxic background and ideas” of the Vermont senator that make him the Trump team’s “ideal Democratic opponent.”

Third Way sounded the alarm in early January about the potential of a “Sanders general election disaster,” and they upped the ante this week with a hard hitting two-pager distributed in Iowa urging caucus-goers to “google Bernie” for the easily available opposition research that will “arm the Trump team with the political equivalent of nuclear weapons,” and, they say, make Sanders “the easiest target for Trump to beat.”

While Trump will lie to discredit any Democratic nominee, “with Bernie, much of what he’d say would be easily backed up. When political charges are supported by evidence, they are very tough to combat,” Third Way President Jonathan Cowan writes.

The charges are familiar: that Sanders is a socialist; that his spending plans are unrealistic and would raise taxes on the middle class; that he has said many problematic things over his long career; that Medicare for All is deeply unpopular, especially in the battleground states of Michigan and Pennsylvania; and that Sanders at the top of the ticket would likely doom Democratic chances of picking up Senate seats in swing states.

Supporters of Sanders may know all this and don’t care, but they’re not the target audience for Third Way’s critique.

“Bernie’s people are immovable, same as Trump’s,” says Matt Bennett, a co-founder of the moderate Democratic group.

“We want to reach Democrats who think it’s going to be relatively easy to beat Trump, and so why not go with the most liberal candidate and shoot for the moon—and those who buy Bernie’s spin that the inverse of Trump is the best candidate, an angry liberal populist as opposed to a right wing populist.”

It’s begun to dawn on Democrats that Sanders could sweep the first three contests: the Iowa caucuses on Feb. 3, the New Hampshire primary on the 11th, and then the Nevada caucuses on Feb. 22. Sanders typically does well in caucuses, where the most highly motivated voters turn out.

It’s not until South Carolina’s primary on Feb 29 that black voters, so far much less enamored of the senator from Vermont, are expected to back Joe Biden’s candidacy. That could be too little, too late for Biden, or anyone else for that matter if Sanders is able to steamroll before then.

“You can’t control for what momentum is built on,” says Bennett. Iowa might not be a clean win; maybe three or four candidates will all be bunched up within a few percentage points. New Hampshire neighbors Vermont, Sanders’ home state, and a win there should be discounted as it was for Massachusetts Senator Paul Tsongas, who won the New Hampshire primary in 1992 only to see Bill Clinton anoint himself the Comeback Kid and turn his second place finish into a win.

Third Way is not alone in trying to put a speed bump in Sanders’ path. A pro-Israel super PAC began airing ads this week questioning Sanders’ electability, and former Obama campaign officials Jim Messina and Ben LaBolt are speaking out about Sanders being the “worst” candidate to go up against Trump.

“All Democrats, even Wall Street-funded groups like Third Way, should be ecstatic to witness this movement attracting new supporters to strengthen the party and expand the electorate,” Sanders campaign manager Faiz Shakir told Iowa Starting Line, an influential news site, earlier this week. “To win seats up and down the ballot, we need to generate excitement and enthusiasm that drives a huge voter turnout among working people, not stifle it to protect special interests.”

For Democrats, taking on Sanders has unique risks. “He’s the Borg, as they say in Star Trek—shoot at him and he gets stronger,” says Bennett. “It’s true when groups like Third Way stir things up, he says it’s the corporate whores, blah, blah, blah. But we’re less than a week out from people actually voting, and the people we’re trying to reach with this last-ditch communication are people who don’t care who we are. This isn’t about us. We want to get the information into their brains.”

The latest UC Berkeley Institute of Governmental Studies poll adds to the mounting panic among moderate Democrats. It shows Sanders leading with 26 percent of the vote in delegate-rich California, which votes on March 3, Super Tuesday. Elizabeth Warren is second with 20 percent of the vote while Biden barely makes the threshold of 15 percent to be awarded delegates. Strong backing among Latinos and young voters is making the difference for Sanders.

Sanders has pretty much gotten a free ride until now with the other Democrats not wanting to alienate him knowing he’s in the race to stay and could be kingmaker for one of them. Instead, he’s the one who’s charting the most obvious path to the nomination