Transcript for Trump bars California from setting its own auto emission standards
with California tonight, telling that state it cannot set its own emissions standards, revoking that state's right to set its own limits for cars and trucks. California's governor calling it a political vendetta and he's vowing to fight back tonight. ABC's Matt Gutman from California. Reporter: Tonight, president trump in California, picking what could be a long legal fight, with this tweet. "The trump administration is revoking California's federal waiver on emissions." Barring California from setting its own auto emission standards, the president said is about making cars safer and cheaper. California leaders saying it's about something else. Pure politics. And politics that could have profound consequences not just in terms of the air we breathe in the state of California, but will impact the rest of the country. Reporter: The EPA is proposing a single national standard for tailpipe emissions, injecting uncertainty into the automotive industry. California leaders say they will challenge it in court. Our message to those to claim to support state's rights, don't trample on ours. Reporter: The latest move against California, part of what the governor here calls the president's political vendetta against the state. The president also hitting California's other big pressure point, homelessness. Suggesting to reporters aboard air force one it hurts the prestige of the major cities, saying "We can't let them destroy themselves by allowing what's happening." We spent two days imbedding with l.a.'s fire station number nine, the busiest station in the country. It serves l.a.'s skid row, where streets and sidewalks are swallowed under homeless encampments. Most of their calls, not fires, but medical. You said that you saw that guy Yes. Reporter: You tended to him yesterday? Yes. Reporter: What was yesterday? Same thing. Reporter: Overdose? Yeah. I don't know how you fix that. Matt Gutman with us tonight from Los Angeles. In addition to this move on emissions, the president and his H.U.D. Secretary now rejecting California's request for additional federal funds to combat homelessness, which the president has brought up on his own. Reporter: That's right, David. And Ben Carson, who toured skid row today, said that federal taxpayers should not have to foot the bill for California's policy mistakes. Policy mistakes that he said helped create this homelessness problem. David? All right, Matt, thank you.
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