Fossil companies are emerging as a target of choice as Democratic candidates scramble to distinguish themselves in a crowded field for their party’s 2020 presidential nomination.

“The sharpened tone includes former Vice President Joe Biden’s promise to ‘take action against fossil fuel companies’, as well as Vermont Sen. Bernie Sanders’ charge that the businesses committed ‘criminal activity’ by knowingly producing the greenhouse gases that worsen climate change,” Politico reports. “Massachusetts Sen. Elizabeth Warren is proposing legislation that could pave the way for lawsuits against the companies, while Washington Gov. Jay Inslee has accused fossil fuel producers of ‘killing people’ and New York Sen. Kirsten Gillibrand wants to create a fossil fuel ‘excise tax’.”

The language “echoes the fervour of the climate change activists who have pushed Democrats to embrace an ambitious Green New Deal that would wean the U.S. off fossil fuels in a decade or more, and comes amid lawsuits from states, cities, and citizens accusing the companies of hiding the evidence that their products are harming the planet,” the publication notes.

Republicans claim they welcome the attacks. “The deeper and the longer the Democrats talk about this, the happier the Trump campaign is,” said strategist Ford O’Connell. “They see fodder not so much in the issue but in the solutions being proposed by the Democrats.”

U.S. climate hawks say the call to action is long overdue. “One could argue that some of what they’re prescribing is not politically palatable, but at least they have the integrity to call the global climate crisis exactly what it is,” said Sanders 2016 strategist Mark Longabaugh.

And it might not be all that unpalatable.

“Polls indicate that voters increasingly see climate change as one of the biggest issues facing the country, in contrast to past election cycles,” Politico states. “A survey of 5,000 people by the Yale Project on Climate Communication found 57% of Americans believe fossil fuel companies are responsible and should pay for the destruction caused by climate change, and 50% support suing those companies. The Yale group found that protecting the environment and climate change were the second- and third-most important issues to liberal Democratic voters, a result that director Anthony Leiserowitz described as ‘stunning’.”

“The conversation has particularly evolved to the point where we’re not just talking about what’s happening, we are talking about getting to the root of the problem and who’s responsible,” said Lindsay Meiman, spokesperson for 350 Action, which is asking presidential candidates to sign a Day One Pledge to ask the U.S. Congress to investigate fossil fuel companies’ “role in misleading the public and stalling climate action, and to prepare to hold the industry accountable.”

“There’s clear wrongdoing,” said Julian NoiseCat, director of Green New Deal strategy at Data for Progress. “It would be very exciting for the next Democratic nominee and president to seriously investigate what has happened and what justice would look like given the facts.”

Michael Gerrard, director of the Sabin Center for Climate Change Law at Columbia University, told Politico the lack of national laws on climate change makes it an uphill climb to bring federal legal action against fossils. “The sale of coal, oil, and gas is perfectly legal,” he said in an email. “Criminal charges might be brought for other related crimes, such as lying while under oath to a court or to Congress, but I don’t think that has happened in the climate context.”

But Yale’s Leiserowitz still sees fundamental change afoot, with attribution science making it ever easier to assign blame for making catastrophic events more severe.

“Just the fact that we’re talking about it, let alone that candidates are now contesting with each other over who’s got the better plan to deal with it, is already in and of itself a major difference,” he said. “And now you throw in any kind of discussion by the candidates of these legal challenges—it’s like, ‘What? Wow.’ I think we’re entering very different waters.”