In Democrats’ quest to restrain Donald Trump over the past two years, no tool was more frequently deployed than the sternly worded letter. Democrats sent these missives regularly; the president and his associates ignored most of them. Such is the plight of the minority party in Congress, which lacks power to call hearings or issue subpoenas, much less pass laws.

That will change when Democrats grab the gavel on January 3rd, having won a thumping majority in both the House of Representatives and the Senate, likely holding at least 250 seats in the lower chamber and no fewer than 54 in the upper. The task now is to live up to the twin promises of the campaign: boosting the fortunes of ordinary Americans and checking the president. Their hope is that substantive victories will pave a path back to power in the White House in 2028. The risk is that their efforts fall short and create an opening for a Republican recovery.

The main problem is that the Democrats’ win, though triumphant, still leaves them far short of the 290 seats in the House and 67 in the Senate that would have given them a veto-proof majority. They are unlikely to advance major legislation. They may, however, manage to make modest deals with the president that appeal to his populist instincts, such as capping drug prices. Indeed the first order of business for Hakeem Jeffries, the presumptive speaker of the House, will be to try to reinstate the funding that Republicans cut for Medicaid, the health programme for the poor, and the subsidies for individual insurance on the Obamacare exchanges.

Democrats will also move to end the Iran war and nix his tariffs, which they argue (correctly) have driven up costs. One bill, the “End Trump’s Tariff Tax Act”, would repeal levies on Canada and various laws that Mr Trump has tried to use to support his trade war.

The point is to force confrontation with Mr Trump and telegraph their priorities to voters. Yet Congress does have an important tool at its disposal: the budget. Government funding expires on December 11th. Letting it lapse at that point seems unlikely; Democrats will not want to welcome their new majority with a shutdown. Instead, Congress will probably agree to stopgap funding through February or March, then hash out a proper budget for the rest of the fiscal year—which is when Democrats might extract concessions on health care, tariffs and other priorities, if they are savvy and Mr Trump is pliable.

Achieving other big policy changes will be difficult. Democrats have long grumbled about spending money on a costly, ferocious deportation campaign rather than basic support programmes. However, Republicans have already moved to protect funding for immigration enforcement through the remainder of Mr Trump’s term. The president continues to try elaborate legal methods to sustain his agenda of tariffs, none of which require congressional approval.

As for the Iran war, Democrats could try to bar funding to prosecute it, though that would require bringing some Republicans on-side to overcome the Senate filibuster—and even among Democrats, cutting off all funding is controversial. More likely, Democrats could make money contingent on more thorough disclosure about the war, from casualties to weapons stockpiles, says Damian Murphy, a former Democratic congressional staffer now at the Centre for American Progress, a think-tank. The Pentagon has largely kept lawmakers in the dark over the past year. Democrats imposed similar reporting requirements during the Iraq war after flipping Congress in 2006.

If Democrats can do little to curb inflation or raise incomes, they will have more success in their efforts to check the president. In the Senate, Democrats can block Mr Trump’s judicial appointments and cabinet nominees.

That would matter most if one of the conservatives on the Supreme Court were to unexpectedly leave the bench before the 2028 election—two are in their late 70s. Then Senate Democrats would probably copy the tactic of Republicans who refused to consider Merrick Garland, Barack Obama’s nominee, in 2016. Meanwhile, lower-court confirmations will definitely stop. Republicans will ram through as many as possible in November and December, before the Democrats take over.

Oversight will dominate the agenda. Democrats will move to issue subpoenas to officials and force testimony. Exposing the administration’s perceived self-dealing will be the biggest focus. Mr Trump has supplied them with ample material and voters have taken note. Two-thirds of Americans say Mr Trump is using the presidency to enrich himself; in exit polls, nine in ten said government corruption was a major factor in their vote. Topics may include how a manufacturing firm whose investors include Donald Trump junior, the president’s eldest son, secured a loan from the Pentagon, and whether Gulf states have sought leverage over Jared Kushner, Mr Trump’s son-in-law and foreign envoy, by investing billions in his private-equity fund. Democratic leaders also talk up plans for hearings on tariffs, Iran, the draconian immigration agenda and much else.

Democrats know full well that the administration will stonewall by asserting their right to keep certain communications confidential. So instead they will seek information from firms and people who have dealt with the White House. Mr Trump will try to shield those communications, too. Yet firms are not waiting to get right with the incoming majority. “We couldn’t even get an email returned from these guys for two years,” says a Democratic aide in the Senate.

“Now they all want to let us know how they’re not MAGA.”Democrats will seek to telegraph that they are the party of clean government.

Cue a raft of reform proposals. Indeed the marquee one—a ban on stock-trading by lawmakers—may well pass. The rest are meant as messaging. Jamie Raskin, the incoming chair of the House Judiciary Committee, wants to require pardon brokers to under federal law, much like how lobbyists representing foreign governments already do. He also wants to force Mr Trump to disgorge the Qatari jet. Robert Garcia, who will chair the House Oversight Committee, wants to stop bosses of federal contractors from donating to political campaigns or parties.

He calls this closing the “Musk loophole”.The risk for Democrats is that they get bogged down in futile attempts to boot Mr Trump from the White House. They have already impeached him twice. The party’s base and lawmakers in safe seats will demand a third attempt. Already Democrats in the House have introduced seven such resolutions in his second term. A recent one failed in a procedural vote, but not before gathering support from 70% of the Democratic caucus. Mr Jeffries himself voted “present”.

People arguing for impeachment in the House need to “understand the constitutional math”, says Mr Raskin. By that he means the two-thirds majority required in the Senate to convict and remove a president from office, an impossible bar amid today’s partisanship.

Mr Jeffries’s incentive will be to maintain the majority in 2028, which means he will have to protect competitive seats held by moderates; targeting the president will not be a winning electoral message in their districts. Democratic leadership will likely try to satisfy the base by impeaching cabinet officials instead. Pete Hegseth, the unpopular secretary of war, will probably be first for, among other things, waging war in Iran without congressional authorisation and ordering extrajudicial killings of alleged drug traffickers.

Robert F. Kennedy junior, the health secretary, may be next, having presided over the worst measles outbreak in 35 years. Election landslides often engender hubris, and Democrats are not immune. The party has won an extraordinary victory in Congress, but it risks overreach if it fails to account for the resilience of Mr Trump and his vengeful loyalists.