Scheduling note: WhatMatters is honoring America's presidents on Monday and will return to your inboxes on Tuesday.

The Trump administration has tossed out the legal basis that allows the federal government to combat climate change, likely kicking off a legal battle between several states, including California, and environmental groups.

As CalMatters' Alejandro Lazo explains, after the U.S. Environmental Protection Agency determined in 2009 that greenhouse gases endangered public health — known as the "endangerment finding" — it had the authority to set the country's greenhouse gas rules for vehicles. This included policies regulating tailpipes, power plants and the fuel economy of cars.

But the Trump administration on Thursday said it was revoking the finding, touting the move as the "single largest act of deregulation in the history" of the U.S.

Gov. Gavin Newsom was quick to denounce President Donald Trump, saying in a statement that he "put corporate greed ahead of communities and families." California Attorney General Rob Bonta also pledged to sue the administration.

As California prepares to dispute the repeal in court, some experts say that this could give states more authority to mitigate the harms of climate change. Much of California's climate policies rest on state laws that have secured federal exemption through waivers. California could argue that it no longer needs federal approval, and therefore can set its own climate rules. 

• Assemblymember Cottie Petrie-Norris, an Irvine Democrat at a California Environmental Voters presser Wednesday: "This is definitely a conversation. So stay tuned."

In the face of federal retreat, another Democratic state legislator, Assemblymember Robert Garcia of Rancho Cucamonga, introduced a bill this week expanding state regulatory powers, specifically affirming the state's authority to curb pollution from warehouses and ports. Said Garcia: "It's no secret that the federal government and California are not seeing eye to eye. … This is an opportunity for our state, for California to step in."

Read more.

U.S. Rep. Kevin Kiley of Roseville split with his Republican party this week by voting against a procedural motion backed by House GOP leadership — laying the groundwork for representatives to reject Trump's tariffs on Canada, writes CalMatters' Maya C. Miller.

Last year, Trump used the International Emergency Economic Powers Act to impose some of his tariffs. Members of the House can challenge "national states of emergency" by introducing a resolution that must be voted on within 15 days. But House Speaker Mike Johnson has used calendar gimmicks to extend the definition of a "day" — effectively delaying Democrats from having their challenges to Trump's tariffs up for consideration.

On Thursday Kiley voted against using the tactic — which has historically been used by both parties — helping Democrats advance an anti-tariff resolution they introduced last year that Trump will likely veto.

Kiley is up for reelection in November, and his district has been drastically reshaped to favor Democrats under Proposition 50. Though he has not stated which district he will seek reelection, his GOP defiance this week is likely part of a political calculus to court independent and Democratic voters.

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A bipartisan group of lawmakers, victim relatives and advocates gathered in Sacramento on Thursday to unveil a package of bills aimed at reducing DUI deaths, report CalMatters' Robert Lewis and Lauren Hepler.

Many of the proposals are in response to issues CalMatters reported in its ongoing License to Kill series, which examines how California's leaders, courts and lawmakers fail to keep dangerous drivers off roads.

Some of the bills include:

• Assembly Bill 1605 that would prohibit people convicted of serious or repeat DUIs from purchasing alcohol by adding a "NO ALCOHOL SALE" sticker to their driver's licenses.
• AB 1686 that would allow prosecutors to charge a second DUI offense within 10 years as a felony. Under current state law, it takes four DUIs within 10 years to be charged as a felony.
• A planned proposal by Assemblymember Lori Wilson, a Suisun City Democrat, that would require license suspensions to start as soon as when a deadly driver is released from prison.

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California's portion of the Public Health Infrastructure Grant — known as "the backbone" of public health nationwide — is at risk of being rescinded after the Trump administration said it plans to pull $600 million in public health funds in four left-leaning states. The grant pays for over 400 jobs in California, including in areas with few health care workers. Read more from CalMatters' Ana B. Ibarra.

California Voices

CalMatters columnist Dan Walters: Newsom's declaration of a surplus following the pandemic fueled a spending increase that has given us a structural deficit ever since.

Reader reaction: Schoolwide phone bans punish students who use their devices responsibly and exacerbate cravings for teens struggling with overuse, writes Evelyn Thill, ninth grade student in San Diego County.