As he runs his third campaign as the Republican presidential nominee, Donald Trump has kept up a dizzying schedule of rallies, news conferences, public appearances and media interviews.

His meandering public speeches have, in recent months, grown longer, more tangential, and darker in tone.

In those many public appearances — and on his Truth Social account — Trump has made a raft of campaign promises, on issues including the economy, immigration and the amount of water that flows through California.

Here is a look at some of Trump’s campaign promises and their chances for success if he is elected.

Ending taxes on Social Security benefits

The promise: Trump has said he plans to eliminate income taxes on Social Security benefits, calling them a “cruel double taxation” of retirees.

Trump — who also has pledged to exempt tips and overtime pay from taxation — began floating the idea of eliminating taxes on Social Security during rallies and on his Truth Social account this summer.

The 2024 Republican Party platform says “President Trump has made absolutely clear that he will not cut one penny from Medicare or Social Security.” But it does not include his pledge to exempt Social Security benefits from taxes.

What Trump has said: “Our seniors have been devastated by inflation. We’re gonna have no tax on Social Security for our seniors. If any senior doesn’t vote for Trump, we’re gonna have to send you to a psychiatrist to have your head examined,” Trump said in Mint Hill, N.C., last month.

The reality: About 40% of people who receive Social Security benefits have to pay federal income taxes on them, according to the Social Security Administration. Revenue from those taxes helps to shore up the Social Security and Medicare trust funds, which are dwindling.

Tax and policy analysts from across the political spectrum have lambasted Trump’s plan, saying it would make an already massive federal deficit even larger and that it would accelerate the insolvency of the trust funds.

The Tax Foundation, a conservative-leaning think tank, called Trump’s pitch “unsound and fiscally irresponsible,” saying it would increase the budget deficit by $1.6 trillion over 10 years.

Changes to the tax code require congressional approval.

Massive increase in tariffs

The promise: Trump, who calls himself the “tariff man,” has floated tariffs of 10% to 20% on all products imported into the U.S. from overseas, and a tariff of 60% or more on China. He has vowed to match other countries’ levies on American goods, saying: “If they charge us, we charge them — an eye for an eye, a tariff for a tariff, same exact amount.”

Trump has argued that other countries are ripping off the U.S. and that higher tariffs would “launch an economic boom,” revive American manufacturing, and lessen the country’s dependence on China.

The former president in September also threatened to slap a 200% tariff on John Deere imports if the farm equipment manufacturer follows through on plans to move some production to Mexico.

What Trump has said: “The word tariff, properly used, is a beautiful word. One of the most beautiful words I’ve ever heard. It’s music to my ears. A lot of bad people didn’t like that word, but now they’re finding out I was right. And we will take in hundreds of billions of dollars into our treasury and use that money to benefit the American citizens. And it will not cause inflation, by the way,” Trump said in a speech in Savannah, Ga., last month.

“A tariff is a tax on a foreign country. That’s the way it is, whether you like it or not. A lot of people like to say, ‘Oh, it’s a tax on us.’ No, no, no. It’s a tax on a foreign country,” Trump said in a speech in Wilkes-Barre, Pa., in August.

The reality: Economists overwhelmingly say that tariffs are the equivalent of a tax hike, with American consumers paying the price for more expensive goods.

The Peterson Institute for International Economics, a nonpartisan think tank, projected that if Trump were to enact a 20% across-the-board tariff along with a 60% tariff on China, it would cost a middle-income household roughly $2,600 a year. Senate Republican Leader Mitch McConnell said in September that he’s “not a fan of tariffs” because “they raise the prices for American consumers.”

Congress has the authority to enact tariffs, but in recent decades, it has delegated considerable power to presidents to impose tariffs without congressional approval if certain statutory conditions are met — such as a threat to national security or harm to domestic industries, said Monica Morlacco, an assistant professor of economics at USC.

In 2018, the Trump administration imposed significant tariffs on thousands of products — including washing machines, solar panels, steel and aluminum — from various countries, notably China, Canada, Mexico, and countries within the European Union. Many affected countries responded with retaliatory tariffs on U.S. exports, sparking a costly trade war.

It is likely that Trump would indeed enact high tariffs in a second term, and that he would try to justify them by claiming there is unfair competition from abroad and that he is protecting U.S. industries, Morlacco said.

Mass deportations

The promise: Trump has proposed the “biggest domestic deportation campaign in American history” to remove millions of immigrants who are in the country illegally. He says he would use the National Guard and local police officers to carry out the removals, which, he has said, would be “starting at noon on Inauguration Day 2025.”

The former president’s chief immigration advisor, Stephen Miller, has said that if an “unfriendly state” like California does not cooperate, then Trump could order Guard units from red states like Texas to cross their borders to carry out deportations.

Trump has not ruled out creating detention camps to hold people awaiting deportation but said the removals would be so fast that there would not be much need for them. Miller, though, has said such camps — “large-scale staging grounds near the border, most likely in Texas” — are part of Trump’s plan.

Trump has claimed without citing a source that more than 21 million people are living in the country without legal authorization. The U.S. Department of Homeland Security, in a report citing the latest available data published in April, estimated there were about 11 million as of January 2022.

Trump says he would first deport criminals and that doing so would be a “bloody story.”

What Trump has said: “They came from prisons and jails; they came from mental institutions and insane asylums. They’re terrorists, they’re criminal street gangs, they’re MS-13. We took millions of people like this into our country, and we’re going to get them out, and we’re going to get them out fast,” Trump said in Mint Hill, N.C., in September.

“We will send elite squads of ICE, Border Patrol and federal law enforcement officers to hunt down, arrest and deport every last illegal alien gang member until there is not a single one left in this country. And if they come back into our country, they will be told it is an automatic 10-year sentence in jail with no possibility of parole. And I’m hereby calling for the death penalty for any migrant that kills an American citizen or a law enforcement officer. With your vote, we will achieve complete and total victory over these sadistic monsters,” Trump said in Aurora, Colo., this month.

The reality: In regard to mass deportations, policy experts and immigration advocates have said it would be extraordinarily difficult, expensive and time-consuming to track down millions of people, deploy the military and law enforcement to carry out raids, transport migrants, and fight court challenges.

Legal scholars say Trump’s promise of mass deportations — cost and logistical challenges notwithstanding — should be taken seriously because Trump and his acolytes are citing archaic federal laws that would give him broad authority to carry out his plans.

Trump has said he would invoke the Alien Enemies Act of 1798 to expel noncitizens who are suspected gang members, drug dealers or cartel members without due process. The law allows for the arrest, detention and removal of people from countries or governments with which the U.S. is at war — or from countries that have engaged in or have threatened an invasion or “predatory incursion.”

Under normal circumstances, the Posse Comitatus Act of 1878 bars the U.S. military — including National Guard troops called into federal service — from taking part in domestic law enforcement. And, typically, one state’s National Guard troops that have not been federalized cannot be deployed by their governor into another, non-consenting state.

But “as soon as the president invokes the Insurrection Act, none of this matters,” said Joseph Nunn, a national security expert with the nonpartisan Brennan Center for Justice at the New York University School of Law.

The Insurrection Act, originally enacted in 1792, “gives the president essentially unlimited discretion to use the military as a domestic police force,” Nunn said.

“The president’s decision to invoke the Insurrection Act is not subject to judicial review,” Nunn said. “Essentially, an ‘insurrection’ is whatever the president says is an insurrection.”

If Trump were to invoke the Insurrection Act and declare that the National Guard was needed to enforce federal immigration law, he could, for example, send Texas troops into California over the almost certain objections of Democratic Gov. Gavin Newsom and likely pushback from the military.

Whether the deportations themselves are lawful and whether it is legal to use the military to carry them out, Nunn noted, are separate legal questions.

Cost estimates vary, but conservative estimates put the price tag of mass deportations at well over $100 billion.

The economic impacts would be huge. In California, an estimated 1.5 million workers — 7% of the state’s labor force — are undocumented, according to the Pew Research Center. The Institute on Taxation and Economic Policy, a left-leaning think tank, found that undocumented workers paid $96.7 billion in taxes in 2022, including $8.5 billion in California.

More water for Californians

The promise: Trump has vowed to bring “water in California at a level that you’ve never seen before.”

Trump said he would deliver more water to California farmers — particularly those in the Republican-leaning, drought-prone Central Valley — and to Southern California cities like Los Angeles, by pressuring Gov. Gavin Newsom to change how the state manages its limited water supply, most of which comes from Northern California.

Speaking at his Rancho Palos Verdes golf club in September, Trump indicated he would revive his first-term fight with California leaders over water allocations and environmental laws meant to protect endangered fish like the tiny delta smelt. He said the state has plenty of water but lets millions of gallons flow into the Pacific Ocean instead of diverting it to farmers and Angelenos.

The former president said he would “revert water up into the hills where you have all the dead forests, where the forests are so brittle” in order to prevent wildfires. He threatened to withhold federal firefighting aid for California unless Newsom agreed to “sign those papers”— an apparent reference to water policy, although he did not specify which papers.

What Trump has said: “Vote for me, California. I’m going to give you safety, I’m going to give you a great border, and I’m going to give you more water than almost anybody has. And the farmers up north are going to be able to use 100% of their land, not 1% of their land.

“And the water’s going to come all the way down to Los Angeles, and you’re going to have more water than you ever saw. And the smelt is not making it anyway,” Trump said at a news conference in Rancho Palos Verdes on Sept. 13.

The reality: As president, Trump worked to relax environmental regulations that limited the flow of water to Central Valley farmers, and his administration was sued by then-California Atty. Gen. Xavier Becerra for allegedly failing to protect endangered fish.

In a second term, Trump would face major legal pushback from state Democrats and environmental advocates if he again gets involved in the state’s long-running, increasingly partisan water wars.

California’s famously complex water system is controlled and financed by a variety of systems at the local, state and federal levels.

Rather than being able to literally divert water to an intended source — like a farm or a “brittle” forest — a president can try to influence water allocations more indirectly, like appointing like-minded people to federal agencies to weaken endangered species laws that affect flow, said Sonja Petek, an analyst for the nonpartisan California Legislative Analyst’s Office who focuses on water and wildlife policy.

“The president’s control over water allocations in California would be fairly limited,” Petek said. “The president doesn’t have a say over who gets water and how much water they would get.”