It’s been a decorous war so far. Sure, some criminal-justice reform advocates have dinged Senator Kamala Harris for her years as a tough district attorney and state attorney general. And Senator Amy Klobuchar continues to absorb shots from anonymous former staffers about her abusive management style. But the 12 declared candidates themselves are still gushing respect for one another. That’s partly because it’s early in the game, and they are focused on building their own name recognition; partly it’s because President Donald Trump is such a massive target and villain. “In 2016, Hillary versus Bernie was a wrestling match,” a senior adviser for one of the leading 2020 contenders says. “And in a wrestling match, you have to size up your opponent and think about your strengths in relation to their weaknesses and vice versa. This one is truly a race. But in a race with, like, 35 cars coming up to the starting line, it is about staying in your lane and going faster than everybody else.”

Yet horns should start blowing soon, when the big, shiny vehicle of Beto O’Rourke steers into traffic. Some of the attacks will be substantive and policy-based, highlighting his Republican-friendly votes on taxes and immigration and trying to tag O’Rourke as a phony progressive. The Bernie Sanders camp threw some preliminary punches at O’Rourke’s record in December, and it will continue to lead the way on the ideological front. “It’s not Bernie’s style to go on the attack, but it is the style of a lot of people who care passionately about rolling back this income inequality,” says Norman Solomon, a liberal activist, writer, and coordinator of the Bernie Delegates Network. “The defenders of the status quo are now promoting certain candidates in the primaries, like Beto. It’s as if 2016 never happened. I give him credit for what he’s saying about the border now, but his district was not purple, it was blue. And he sucks on economic issues. We’re capable of electing somebody way more progressive than O’Rourke.”

A particular emphasis will be on the campaign money that O’Rourke has collected from gas and oil-industry executives. “Not much of that stuff got aired in the Texas Senate race, particularly on fossil fuels,” a Democratic consultant says. “There’s a fair amount still hanging out there.” Washington Governor Jay Inslee, one of the newest official entrants in the Democratic field, is making the urgent need for climate-change action his signature issue. “I don’t know the circumstances of Beto’s donations, but I have pledged not to take fossil-fuel money and not to take corporate PAC money,” Inslee tells me after visiting an Iowa solar-panel plant. “I think it’s very important to break the stranglehold of the fossil-fuel industry on our economy and on our political system, because we have to do a lot to right the imbalance where we have handed out giant subsidies to the fossil-fuel industry while starving the clean energy sources.”

Ben LaBolt, a former campaign and White House aide to Barack Obama, says O’Rourke will need to have good answers for those criticisms and, more important, a credible pitch on why he can get things done in polarized Washington. But ultimately, those prosaic points may not matter much. “I don’t think there’s anything in his record that’s definitive, like voting for the war in Iraq,” LaBolt says. “And the people who came out to support Beto, particularly the young people, were doing so not based on a list of particular issues or votes but because he had a unique generational appeal and motivational prowess. He tapped into the type of campaign that R.F.K. ran, that Obama ran: ‘We’re better than this.’”