Republican Donald Trump campaigned on a promise to shake up Washington and as president the brash real estate mogul will be in a position to dramatically change how the United States handles immigration, trade and a range of other policies.

Yet many of his more ambitious proposals will require cooperation from Congress. While he will likely enjoy a post-election honeymoon with congressional Republicans, a long-lasting romance is far from guaranteed, given his uneasy relationship with congressional leaders and some basic ideological differences he has with Republican orthodoxy.

Following is an overview of Trump’s top domestic policy plans, based on the sometimes vague details of his agenda, and their likelihood of success:

Trade

In his campaign, Trump argued that international trade agreements had hurt U.S. workers and the country’s competitiveness. He has promised to “get tough” on China, withdraw from the 12-nation Trans-Pacific Partnership, or TPP, which is still not finalized, and renegotiate or scrap the North American Free Trade Agreement, the 1994 free-trade deal with Mexico and Canada.

As president, Trump does have some power to raise tariffs on countries such as China. He could delay the TPP, as well, even if Congress approves it.

Economists have warned that such moves would damage the economy by forcing consumers to pay dramatically higher prices on everything from refrigerators to T-shirts. U.S. exports, such as airplanes and soybeans, would likely suffer as well.

Immigration

On the campaign trail, Trump has promised to build a wall along the Mexican border, deport millions of undocumented immigrants and ban immigration from countries that have been “compromised by terrorism.”

Those policies would not come cheap. Trump has estimated the wall would cost $8 billion to $12 billion. Other estimates have run much higher.

Politico estimated it would cost at least $166 billion to deport all of those in the country illegally and complete a border wall. While many congressional Republicans support those policies, they might blanch at the cost.

Trump has said he would force Mexico to pay for the wall, but he has no power to force another country to spend money on something it does not want.

More broadly, Trump could shift the broader debate over immigration, empowering skeptics like Republican Senator Jeff Sessions of Alabama, who want to reduce overall immigration levels and reduce the number of skilled guest workers. That would be a blow to business groups and Hispanic advocates who have sought to relax immigration laws.

 

Healthcare

Trump has promised to repeal President Barack Obama’s signature Affordable Care Act, popularly known as Obamacare, and replace it with a plan that would give states more control over the Medicaid health plan for the poor and allow insurers to sell plans nationally.

He would need Congress to act, and Republicans could have difficulty getting the 60 votes needed to advance a repeal effort through the 100-seat Senate.

Republicans could face a public backlash if they repeal a law that has provided healthcare to millions of Americans.

A Trump administration would have plenty of other opportunities to undermine Obamacare, however, by appointing officials who are not committed to its success.

Taxes and Spending

Trump has vowed to make deep tax cuts, while also promising to protect popular health and retirement programs that account for more than a third of U.S. government spending.

That combination of policies would massively increase the national debt, according to the nonpartisan Center for a Responsible Budget.

He has also proposed increasing spending on the military and infrastructure, but has said he would reduce spending on categories other than health and retirement by 1 percent each year.

On taxes, he would get plenty of help from Republicans in Congress, who have been laying the groundwork for a tax-code overhaul that would lower rates and close loopholes. But they will encounter fierce resistance from homeowners, businesses and other interest groups that benefit from current tax breaks.

Trump’s promise to protect entitlement programs will rile fiscal conservatives, who worry they will swamp the federal budget in the decades to come. But those programs are popular with the American public.

Wall Street Regulation

Trump has promised a “dismantling” of the 2010 Dodd-Frank financial reform law enacted following the financial crisis, but has given few details.

The Republican Party’s platform calls for reinstating Glass-Steagall, the 1930s-era law that forced the separation of investment banks from deposit-taking institutions. Trump’s former campaign manager, Paul Manafort, said in July that his campaign backed that change.

Republican lawmakers have so far been unable to undo many of their most-despised pieces of the Dodd-Frank law, and many in their ranks oppose a return to Glass-Steagall.

Islamic State

Trump has offered few details about his plans to fight Islamic State but has said he would “knock the hell out of” the militant group. He says he is keeping the details of his strategy a secret so as not to disclose them to the enemy. Trump has said if he wins, he would give U.S. generals 30 days after he takes office on Jan. 20 to propose their own plans.

Trump has said he opposes accepting refugees fleeing violence in Syria, and instead has said he would create “safe zones” there, which he says would be funded by Gulf states.

Obama has said a safe zone in Syria would require a large U.S. military commitment, something that could prove to be unpopular with Americans weary of lengthy wars in Iraq and Afghanistan.

Russia

Trump has said he would have a “very, very good” relationship with Russia.

Trump has said could work with Russia to combat Islamic State. He also said he would look into recognizing Crimea, seized from Ukraine in 2014, as Russian territory and lifting sanctions on Russia imposed by Western nations for what they called an illegal land grab.

Trump has criticized the North Atlantic Treaty Organization, saying some U.S. allies have not met their defense commitments. In July, he said if Russia attacked a NATO member, he would consider whether the country has paid up before providing defense.

NATO leaders say the sanctions against Russia are key to persuading it to change that country’s behavior in Ukraine, where it has backed ethnic Russian separatists, and that the alliance has long been focused on fighting international terrorism.

Supreme Court

With one vacancy on the Supreme Court and several more likely in the coming four years, Trump will have a chance to put a conservative stamp on the nation’s courts for decades to come.

His list of potential nominees has won praise from conservative activists and Republicans in the Senate, who will be eager to help him in that area.