WASHINGTON—Democrats captured control of the House and Senate in Tuesday’s election with a sweeping national wave that ousted dozens of Republicans. What will they do now?

President Trump will still have a veto pen for the next two years, limiting Democrats’ ability to enact laws that reverse his policies and setting up clashes that could be even more intense than the conflicts between Trump and Democrats when they controlled the House in 2019 and 2020.

But Democrats enter the new Congress with extraordinary momentum and Republicans reeling after surprise losses.

“This is a change election, and we understand as House Democrats that we need to deliver dramatic change,” House Minority Leader Hakeem Jeffries (D., N.Y.) said late Tuesday. “Things are broken. We need a Congress that puts the American people first.”The new configuration of government—with Jeffries poised to become House speaker and Chuck Schumer (D., N.Y.) set to be promoted back to Senate majority leader—will give Democrats a chance to make some points and show voters what they would pursue if their party gained full control of the government in the 2028 election.

And they will have to negotiate with Trump and Republicans over must-pass items such as legislation to keep the government open and funded.

“Senate Republicans will not stand idly by as the far-left, socialist wing of the Democrat Party attempts to unwind everything we’ve done,” Senate Majority Leader John Thune (R., S.D.) said. “Thankfully, we still have President Trump in the White House, and we’ll work with him to stop the worst impulses of Democrat extremism.”Here is a quick look at some top Democratic priorities.

Republicans used their slim majorities to push through a major tax-and-spending law last year. All Democrats voted no on the “one big, beautiful bill,” and they have vowed to try to reverse much of that legislation.

They will aim to undo changes to Medicaid that require recipients to work and are slated to take effect soon, as well as changes to nutrition-assistance policies that have contributed to a 13% reduction in food-stamp rolls. They also will try to revive Obamacare health-insurance subsidies that Democrats expanded during Joe Biden’s presidency and that lapsed under Trump.

Democrats also might attempt to undo some of the tax cuts that Trump signed into law, particularly the ones that benefited high-income households and corporations.

Democrats expect to use their new majority to conduct oversight, and they will have subpoena power when they enter the majority. The frustrated letters they have sent to the administration over the past two years will turn into demands and hearings.

“Lawyer up,” Rep. Robert Garcia (D., Calif.), the likely chairman of the House Oversight Committee, said late Tuesday. Sen. Ron Wyden (D., Ore.), who would become chairman of the Finance Committee, tweeted a single word: “Subpoenas.”They are likely to investigate Trump’s cryptocurrency dealings, his family’s business ties, his construction projects in Washington, D.C., his acceptance of a Qatari jet, the tax-immunity deal he struck with his own administration and many other controversial subjects that Republican lawmakers haven’t examined.

Elon Musk, the Trump-allied billionaire who led a government-reduction effort early in the administration, is also likely to get scrutiny, particularly for his involvement in slower Starlink speeds that impaired Ukrainian war activity.

Lawmakers have taken mixed stances on impeaching Trump, after neither of his first-term impeachments yielded a conviction and removal. But they have their eyes set on impeaching other administration officials, including Defense Secretary Pete Hegseth.

Democrats also are likely to focus on artificial intelligence by bringing in top executives to testify about their close relationships with the White House and pushing for the first federal regulations setting guardrails for new models. AI regulation has become more of a priority for many lawmakers after a wave of hacks by recent models and warnings from industry researchers that the rapidly evolving technology could be capable of destroying humanity within the next decade.

Progressives have also proposed bills targeting the data centers underpinning the AI boom, hoping to curtail their power usage and address a recent backlash that swept across the country.

Trump’s two main unilateral initiatives—the Iran war and the tariff expansion—helped push prices up and propel Democrats to victory.

“We do have to look at every available legislative mean in order to do what the American people want us to do, which is bring an end to this reckless, unnecessary war,” Jeffries said in a recent television interview.

But stopping the war or reversing the tariffs will be difficult because of Trump’s national-security powers, his ability to veto legislation and his support among Republicans. Democrats could attempt to use Congress’s power of the purse, restricting funding for Trump initiatives they oppose. But they would have to risk government shutdowns or criticism that they’re harming the troops.

Social Security is heading toward insolvency in 2032, and Democrats may take a shot at legislation that would stave off the automatic benefit cuts that would bring. Many of them favor raising the earnings cap—now $184,500—where payroll taxes stop.

Jeffries has talked about expanding the low-income housing tax credit, the earned-income tax credit and the child tax credit.

With Senate control, Democrats will be able to block Trump’s judicial and executive-branch nominees, including any Supreme Court picks. Republicans will likely push through as many confirmations as possible before they lose power Jan. 3. But once vacancies emerge, the partisan divide will either mean acting officials in key administration positions or compromise nominees who can satisfy Democrats.

There are potential areas of compromise between Trump and Democrats, including support for farmers, a tax credit for film production and an overhaul of permitting rules for major projects.

Conflict is likely over must-pass legislation. Government funding is scheduled to lapse in mid-December. And Congress also must raise the debt limit by some time in 2027. If those fundamental tasks don’t get done under Republican majorities in the next two months of the lame-duck Congress, Trump and Democrats will have to figure out a path forward.

Beyond disputes over the amounts of funding, Democrats have been frustrated by the administration’s actions to rescind or change spending levels approved by Congress. In the spending-bill fights, they may seek additional guardrails to prevent Trump and budget director Russell Vought from sidestepping Congress, either by refusing to use money directed by Congress or by spending funds that Congress didn’t approve.

The must-pass bills could also become the fighting ground for Democrats’ demands on the Iran war, tariffs and other issues where they’re seeking leverage over Trump. During Trump’s first term, right after Democrats won the House in the 2018 election, Trump triggered a government shutdown by insisting that Congress include border-wall funding in a must-pass spending bill.