Many of President Trump’s plans aren’t possible without help from state leaders — who have the power to enable or block White House goals.

Take Trump’s deportation plan, what Florida Gov. Ron DeSantis says would be the “largest mass deportation program in American history.”

“That is not possible to be achieved unless states like Florida actively work to facilitate the federal operation,” the Republican governor said recently when announcing an agreement with federal officials for the Florida Highway Patrol to carry out immigration enforcement.

Not just a matter of manpower, it’s also a question of authority. The federal government is powerful but states have jurisdiction over cities and counties, police, schools and health departments. Think back a few years ago when governors took their states in different directions on Covid shutdowns and vaccine requirements.

In contrast to DeSantis’ support, last week Trump had a public dispute with Maine’s Democratic Gov. Janet Mills over whether her state will adopt Trump’s policy on transgender students in sports. “See you court,” the governor told the president during a White House meeting with governors.

The U.S. was created with the idea that states have power except in areas spelled out by the U.S. Constitution. Local officials, like police and sheriffs, are largely governed by local and state laws, not federal mandates.

And then there’s the politics. For now, Trump and his supporters have political momentum, saying the election win endorsed their agenda. Democratic-led states have challenged some of the policies in court. But much of it will rise or fall on what governors and state legislatures do. Here is a look at some of the issues in play.

States can order police to support deportations in ways federal officials can’t

The federal government has the responsibility for protecting U.S. borders but that doesn’t mean it can force local law enforcement to join in.

“The federal government actually is very limited in forcing states and localities to do anything,” says Rick Su, a law professor at the University of North Carolina. But state lawmakers do have the authority to make police and sheriffs participate in immigration enforcement — such as detaining people for immigration violations.

To enable that, Florida, like several states already, just made it a state crime for someone to be in Florida without legal status in the United States. It means local police can charge people with a misdemeanor on the first offense and a felony after that.

George Walker IV WPLN News

Ashley Warbington is removed from a House committee meeting on immigration by State Troopers during a special session of the legislature Wednesday, Jan. 29, 2025, in Nashville, Tenn.

Tennessee lawmakers, urged on by Republican Gov. Bill Lee, last month made it a felony for local elected officials to vote for sanctuary policies, which are banned in the state. In Alabama, one proposal would make it a crime to shield or harbor someone without legal immigration status.

And Democratic-led states have used their power to oppose deportations going back to the first Trump administration. Cities have adopted sanctuary policies and state lawmakers can prohibit police from detaining people on federal immigration charges.

But they can’t interfere with the U.S. Immigration and Custom Enforcement, or ICE, carrying out its federal duties. And the politics here can be hard for Democrats right now. National polls show much of the public supports the idea of deportations and “sanctuary” policies tend to be unpopular.

Trump wants to overhaul American schools but that’s largely in local hands

Trump signed an order encouraging the use of tax money to pay tuition for children attending private schools -– the idea broadly called school vouchers or, by supporters, school choice.

“What the administration is signaling is that they want to bring education, freedom and choice and these dollars closer to each student,” says Lee Schalk, senior vice president of policy at the American Legislative Exchange Council, which advises legislators on laws to limit government and promote “education freedom.”

But much of Trump’s plan relies on states. Lawmakers, mostly in Republican-led legislatures, have already brought some form of vouchers or school choice to many states. Texas Gov. Greg Abbott is pushing lawmakers to start a voucher program that could send $1 billion a year to private schools.

Many Democratic-led states have blocked voucher programs and the idea has usually lost when put to voters directly, amid concerns by both Democrats and Republicans that it’ll drain money from public schools.

One thing Trump could do is persuade Congress to pass tax breaks for groups that can then subsidize tuition. A plan from his last administration would have cost about $5 billion in tax revenue but would have provided tuition for hundreds of thousands of students (about a million of the country’s 50 million schoolchildren get vouchers currently).

Trump also threatened funding cuts to “end radical indoctrination” in schools. But state and local governments control school curricula and they raise more than 80% of their own money.

Meanwhile, some Trump allies call for closing the U.S. Department of Education. That would likely lead to less oversight on the few areas where the federal government does have power –- especially preventing discrimination — and give state leaders yet more control over schools.

Trump won support over concerns about crime but law enforcement is largely local

Crime rose during the Covid pandemic and most crime has dropped in many areas since. But it was a recurrent theme throughout the Trump campaign, which criticized the Biden White House and local officials for criminal justice policies it said were too soft.

“Now the pendulum’s swinging back to normal. Thank God. Because people, especially in blue cities, have realized, look, this is not what we voted for,” says Charles “Cully” Stimson, senior legal fellow at the Heritage Foundation, the research group that compiled the Project 2025 plan for government overhaul written in part by people who subsequently joined the Trump administration.

But, as Stimson notes, the vast majority of crimes are prosecuted at the local level by prosecutors in counties and courts across 50 states. And state lawmakers set the rules for them.

States led by both parties — and their voters in referendums — have already been toughening crime laws. California toughened penalties for drug crimes and shoplifting. Republican-led states have been looking at ways to carry out more executions. While some states and localities eliminated cash bail requirements on some crimes, legislatures in other states have looked at ways to toughen bail requirements.

Abortion rights, vaccines, fluoride are decided at the state and city level

President Trump has taken credit for the U.S. Supreme Court decision to end the federal right to abortion in 2022 because of his choice of justices in his first term. Reproductive rights are a stark example of an issue that’s up to state lawmakers, as evidenced by the constantly shifting patchwork of abortion laws across the country.

Going further, states are now re-interpreting their powers over other medical treatments, from whether they can ban medications used for abortions to transgender care. Nicole Huberfeld, professor of law at Boston University’s law school and co-director of the school’s Program on Reproductive Justice, says she’s tracking court cases “where states are claiming that they have power to decide which kinds of medical care should be lawful and the federal government does not.”

After Trump signed an executive order threatening to cut federal funds from hospitals that provide transgender care, Democratic state attorney generals in New York and California told hospitals they were still obligated by state law to continue the treatment.

Meanwhile public health matters like vaccine requirements for public school children and workplaces are at play in legislatures around the country.

The common practice of putting fluoride in water to improve dental health — something criticized by new Secretary of Health and Human Services Robert F. Kennedy Jr. — is controlled by states and cities. Several state legislatures are considering bills to prohibit its use.