He’s a 77-year-old socialist who’s abrasive when he’s in a good mood, and who’s still blamed by many Democrats for Hillary Clinton losing to Donald Trump. But go ahead, try to argue that Bernie Sanders isn’t the front-runner in the 2020 Democratic race right now.

After making his second presidential run official on Tuesday, Sanders blew past every other announced candidate’s early fundraising numbers—$3.3 million in the first few eight hours, more than double the huge $1.5 million Kamala Harris raised in the whole first day—and he’s expecting to easily hit the 1 million website sign-ups he asked for as a first show of support for his campaign.

For all the more conventional Democrats who greeted the news of his candidacy with sighs of “Oh no!” or “Give me a break,” no one else running could do that.

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Then there’s where he stands in early polls, behind only Joe Biden. Or the argument Sanders’s own pollster has been making: that he will have surprising strength in parts of the country where he connects with many of the same disaffected voters who backed Trump, or who were too turned off by what’s become of politics to vote at all in 2016.

“Short of Joe Biden entering the race, Sanders on paper starts off with more advantages than anybody else. He’s got the largest list; he’s got the most intense following that has stayed with him since 2016; he has a proven ability to fundraise from his small-dollar base,” said Brian Fallon, a Democratic strategist who was the spokesman for Clinton, leading the public charge against Sanders last time around. “He’s in the exact opposite position that he started off the 2016 campaign in.”

The Democrats running against him assume that this won’t last. But he’ll raise millions, get 20,000 people at his rallies, and make them all look junior varsity in comparison. Still, they’re confident that he won’t be able to maintain that over the next year.

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Sanders running when he’s part of a big field of enticing candidates is a whole lot different from Sanders running as the single fresh alternative to a candidate who never inspired much passion throughout her entire career. He could burn out, get eclipsed by some of the newer forces in the party, and have to answer for all the parts of his record and background that didn’t get full scrutiny when he was a novelty nowhere near winning in 2016.

If nothing else, there could certainly come a point late in the game, much like what happened with Howard Dean in 2004, when Democratic voters look at him and say they just can’t take seriously the idea of Sanders actually beating Trump, or actually being the commander in chief and sitting behind the Resolute Desk in the Oval Office as the 46th president of the United States.

At least that’s what his rivals are telling themselves. Because that’s how races have always gone up to this point. Except, that is, for 2016, when Sanders became a bizarre breakout sensation and the country put Trump behind that desk as the 45th president.

No matter what, his candidacy seems set to reshape the dynamics of the race.

Sanders has moved quickly in an attempt to show that he’s a more serious candidate than four years ago, when he announced his campaign during a break from the Senate floor, gave a few harried answers to the questions from the few reporters who had showed up, and then said he had to get back to vote.

This time, he started with a carefully constructed rollout, with a slick announcement video, a sit-down interview on CBS This Morning, and a media tour. “Sisters and brothers,” he wrote to his huge email list Tuesday morning, “together, you and I and our 2016 campaign began the political revolution. Now, it is time to complete that revolution and implement the vision that we fought for.”

A full operation is being put together, with the assumption that he will have well over $200 million in online fundraising to draw from. That includes top leadership of the campaign meant to illustrate the diversity of his support, demographically and geographically. Faiz Shakir, a former aide to Harry Reid, is leaving his job as the political director of the American Civil Liberties Union to be the campaign manager. In addition to his deep political experience, he will be the first Muslim presidential-campaign manager in history. Analilia Mejia, an organizer of Colombian and Dominican descent who most recently directed the Fight for $15 and Earned Sick Days campaigns in New Jersey and previously worked for the New Jersey Working Families Party, will be the political director. The deputy political director will be Sarah Badawi, who was most recently the government-affairs director for the Progressive Change Campaign Committee, a liberal group that led the effort to draft Elizabeth Warren into the 2012 Senate race, and later worked on her campaign.

Their organization will send out an array of emails, videos, and Twitter-friendly GIFs, which Sanders and his team hope to use to capture the sensation of his 2016 campaign and turn it into an overwhelming movement.

All this will build to a big kickoff rally.

“Bernie Sanders is always an underdog because he is fighting against large special interests who don’t want to see his agenda succeed. He’ll be the underdog until the day he wins,” said Representative Ro Khanna, a California Democrat enthusiastic about Sanders’s announcement. “He’s the front-runner in terms of grassroots energy and a small-dollar army—we’ve seen how decisive that is.”

The darkness settled in at Warren’s headquarters weeks ago, and by Tuesday morning, Warren advisers were thinking that the upside of Sanders’s candidacy is that at least there will be two strong voices for real structural reform in the economy and political system. While her goal remains winning the White House, she and her aides have had to rethink how she’s going to get there. Sanders will massively out-raise and outperform her for months, Warren advisers think. But over time, if she is able to build up the staying power, there might be a chance for her to have a late second wind, particularly if Sanders collapses under either his own weight or late skepticism about him becoming the nominee, people around her believe. In that scenario, she’s like John McCain in the 2008 Republican primary, able to surge as an acceptable alternative once people try out Sanders and other candidates and realize they don’t like any of them. Sanders could serve as a buffer for anyone who thinks that Warren is too left, or too old, or doesn’t have enough of a claim on the women’s vote given the other female candidates in the race.

Khanna argued that the two won’t split votes.

“Running for president is something deeper. I don’t think you have just a cut-and-paste Let’s see who has what percent of the base and how they overlap. I think it’s about do you meet the moment, and does your vision inspire people?” he said.

A Warren spokeswoman declined to comment on what impact Sanders’s presence in the race would have on her campaign.

In the meantime, several other candidates are salivating over how they expect the two to destroy each other. Among those potentially positioned to do best over a scramble on the left flank are Cory Booker and Kamala Harris, who both have progressive credentials but are campaigning to build strong and more diverse foundations of support.

Or as Harris greeted the news of Sanders’s entry on Tuesday morning while at a campaign stop in New Hampshire, “The more the merrier. I think it’s great.”

That will likely leave little room for some of the more left-leaning potential candidates who have been considering jumping in, most prominently Senator Sherrod Brown of Ohio and Senator Jeff Merkley of Oregon. Congresswoman Tulsi Gabbard of Hawaii will likely face the same problem distinguishing herself now that Sanders is in the race.

But the moderates will rejoice, hoping that voters take notice of how the Trump campaign quickly responded to the Sanders launch: “Bernie Sanders has already won the debate in the Democrat primary, because every candidate is embracing his brand of socialism. But the American people will reject an agenda of sky-high tax rates, government-run health care and coddling dictators like those in Venezuela. Only President Trump will keep America free, prosperous and safe.”

If beating Trump is the priority, the moderates want primary voters to think that nominating Sanders would be playing right into Trump’s clear plans to spend the next 20 months pumping up his modern-day Red Scare. That’s the theoretical space for Senator Amy Klobuchar of Minnesota, who is pitching herself as a pragmatist. She said at a CNN town hall on Monday night that she won’t support Medicare for all and that she would only support free college tuition “if I was a magic genie.”

But the person most closely watching Sanders’s announcement is probably Biden, who’s been going over polling data and election results he believes show that votes are not as far left as the media attention to things such as Medicare for all and the Green New Deal would suggest.

The former vice president is deep in final deliberations about whether to run again, but he feels sure that Sanders’s agenda will be both the wrong policy for the country and the wrong politics to defeat Trump.

“To be sure, there’s anxiety about what the future holds, and caution about what our rapidly changing world means to families who are being left behind,” Biden said on Saturday at the Munich Security Conference, in a speech full of lines that could have been from an announcement. “This fourth industrial revolution is causing great anxiety, and I think is part of the reason for so much of our uncertainty.”

The Biden spokesman Bill Russo declined to comment on how Sanders’s announcement shapes his thinking.