President-elect Trump and Congress have promised sweeping changes on several issues, without Democrats’ help. Here are some major arenas in which they have vowed action:

Immigration

Trump said he would sharply curtail the refugee flow and start a nationwide crackdown on illegal immigration. He will bring a nativist vision to the White House, regarding immigrants warily as competitors for American workers and treating refugees as potential terrorists.

He has promised to start construction right away on a wall across the Southwest border. He said he would quickly cancel a program Obama put in place by executive action that gave protection from deportation and work permits to about 800,000 unauthorized immigrants who came to the United States as children. He has also said he will temporarily halt all Syrian refugees coming to the United States.

Climate change

Trump has repeatedly denied the science of human-caused climate change, incorrectly calling it “fictional” and saying it was a hoax created by the Chinese. While some legal and procedural roadblocks would impede a complete gutting of Obama’s existing climate change regulations, Trump could significantly weaken or slow them. Trump has vowed to “cancel” the Paris Agreement, though that would not in fact be possible. The head of environmental policy on his transition team is Myron Ebell, who has gained national prominence for his polarizing skepticism of climate science.

Health Care

Trump has promised to repeal the Affordable Care Act, and Republicans in Congress have shown the way. Republicans will not have the 60 votes in the Senate needed to pass most major legislation, but through a parliamentary procedure called budget “reconciliation,” they have already done a dry run to gut the existing law without facing a Democratic filibuster. Many provisions of the health law are now deeply embedded in the nation’s health care system. Uprooting them would be a complex political and logistical challenge.

Economic Policy

Republican control of Washington sets the stage for a sweeping shift in economic policy. Trump has proposed a fairly standard set of conservative prescriptions, such as lower taxes and less regulation, with one notable departure: a promise to reduce trade with other nations. The nonpartisan Tax Policy Center estimated that Trump’s plan would cut federal revenue by $6.2 trillion over the next decade. Trump and his advisers have insisted that these cuts would not increase the federal debt, in part because they say faster growth would increase tax revenue. Previous tax cuts, however, have not produced anything like the projected increase. He has also specifically promised to reverse some new environmental rules, such as the climate change regulations on power plants.

New York Times