Within hours of winning control of the House and the Senate on Tuesday, 3 November 2026, Democrats began describing what they would do with their new power, and immigration enforcement sat near the top of almost every list. Then, on Friday, President Donald Trump named Stephen Miller, the principal architect of his deportation agenda, as his next White House chief of staff, starting on Monday 9 November. The two events set up the defining collision of the next two years: an opposition Congress that believes voters rejected mass deportation, and an executive branch that has signalled it will not slow down.
The question that matters is not whether Democrats are angry, but what a congressional majority can actually do to an enforcement apparatus that is already funded, staffed and run from the White House. The answer, on the public record so far, is that Congress can expose a great deal and stop rather little, at least without the President's consent.
Democrats begin from a stronger political position than they have held on immigration for years. According to The AP Voter Poll, a survey of more than 100,000 midterm voters, about six in ten said the administration's immigration enforcement had "gone too far," and a similar share disapproved of how Immigration and Customs Enforcement was doing its job. About six in ten also said immigrants do more to help the country than to hurt it. For a party that spent the Biden years on the defensive over border crossings, those are numbers that invite action.
The first tool is oversight, and it is the one Democrats will reach for immediately. Rep. Robert Garcia of California, who is expected to chair the House Oversight Committee, greeted the results with a two-word statement: "Lawyer up." The Guardian reported that he specifically warned Miller and promised to investigate his role in the deportation campaign. Rep. Bennie Thompson of Mississippi, who will seek the chairmanship of the House Homeland Security Committee, said the administration "will finally be faced with real oversight" and, according to Federal News Network, has already written to Homeland Security Secretary Markwayne Mullin demanding written confirmation that the department will preserve records and asking for outstanding documents by 2 December.
The likely targets are already visible. The Associated Press reported that investigations could examine the Department of Homeland Security's purchases of large warehouses to hold detained immigrants, whether ICE cut corners while hiring thousands of new deportation officers, and deaths in detention. Federal News Network reported that ICE has more than doubled in size by hiring 12,000 new personnel, and that Democrats want to know how the department has spent the money it received under the 2025 One Big Beautiful Bill Act and this year's Secure America Act. Rep. Delia Ramirez of Illinois, expected to lead the Homeland Security Committee's oversight subcommittee, has said she will request testimony from Miller, Mullin, former Secretary Kristi Noem, border czar Tom Homan and former Border Patrol commander Gregory Bovino, and subpoena them if they refuse.
The difference between this and the past two years is the subpoena. The AP noted that Garcia and Sen. Richard Blumenthal of Connecticut held shadow hearings in the minority, featuring relatives of people killed during enforcement operations, a whistleblower on ICE training and American citizens swept up in raids. No Republicans attended, and Democrats could not compel witnesses. From January they can.
The second tool is money, and here the limits begin. Congress controls appropriations, but much of the money for the current enforcement push has already been provided. According to the AP, Republicans in the summer of 2025 approved $150 billion to expand detention capacity, finish the border wall and hire more deportation officers, and earlier this year they frontloaded routine funding for ICE and Border Patrol for the next three years. A new majority cannot easily claw back funds already enacted into law without passing a bill, and any bill needs the President's signature.
That is the third and hardest limit: the veto. Trump remains in office until January 2029, and the AP noted that he can veto any Democratic legislation. Overriding a veto requires two-thirds of both chambers, a threshold that depends on Republican votes the new majorities do not have on immigration. Democrats can attach conditions to future spending bills and threaten shutdown fights, but with enforcement funding locked in for years, the usual leverage of the annual appropriations cycle is weaker than it looks.
Andrea Flores, a former policy adviser in the Obama and Biden administrations, summarised the fear on the left to the AP: "My fear is that enforcement will get worse. And the country will also see that Congress does not have many tools to stop the executive branch because the executive branch power on immigration has grown so vast." Homeland Security Secretary Mullin, for his part, wrote on social media that "deportations will continue."
The Republican response is already being organised. Fox News reported that House Majority Leader Steve Scalise wrote to committee chairs on Thursday urging them to "maximize our remaining days in power to prepare for what is coming." His guidance asked them to take inventory of investigations Democrats have pursued in the minority, identify who is on Democrats' target lists, and review how recent Supreme Court rulings and a Justice Department memo on executive privilege could bear on future probes. "They will weaponize every single gavel to appease their radical base," Scalise wrote. A spokeswoman for House Judiciary Committee Democrats replied that "the cover-up expires with the Republican majority."
Executive privilege is the battlefield to watch. Subpoenas to a sitting White House chief of staff are a different matter from subpoenas to a Homeland Security official, and past administrations of both parties have fought congressional demands for senior aides' testimony through the courts for months or years. Democrats' oversight calendar is therefore likely to be shaped as much by judges as by committee chairs, and the most productive early targets may be agencies, contractors and spending records rather than Miller himself.
Conservatives also make a substantive argument, not merely a procedural one. Fox News reported that several Democrats who campaigned on affordability pivoted within hours to promises of subpoenas, and that Republicans seized on the shift. Rep. Analilia Mejia of New Jersey wrote that Democrats would "toss out subpoenas like Mardi Gras beads"; Rep. Tony Wied of Wisconsin replied that it showed Democrats "have no plans to make life better for you." The risk for the new majority is real: voters who backed Democrats on prices may tire of a Congress that looks like a standing tribunal.
Some Democrats see that risk and want a positive agenda alongside oversight. Sarah Pierce of the think tank Third Way told the AP that the party should "lean into oversight" but "couple that with a proactive vision for what immigration should look like in the United States." Rep. Gabe Vasquez of New Mexico suggested framing reform through affordability, for example with a new visa class for workers who care for children or the elderly. "This cannot be a third-rail issue for Democrats," he said. Sen.-elect James Talarico of Texas has spoken of comprehensive reform including a pathway to citizenship for long-settled undocumented immigrants.
History is not encouraging on that front. The last serious attempt at comprehensive reform, in 2013, passed the Senate and died in the House. A Democratic Congress could pass such a bill in 2027, but it would face a near-certain veto unless the White House sees advantage in a deal. Trump said shortly after the election that he was prepared to work with Democrats on certain issues, naming immigration among them; the promotion of Miller days later suggests the terms of any deal would be narrow.
The restrictionist side, meanwhile, is racing the clock. The AP reported that many administration supporters want the outgoing Republican Congress to use the lame-duck session to write enforcement changes into law, such as tighter asylum rules or employer verification, so that a future administration cannot reverse them easily. NumbersUSA displays a countdown on its website urging lawmakers to "make border security permanent." Its co-president, Jeremy Beck, said that if this Congress does not act, it "will have failed to meet the moment."
Put together, the picture is of two branches preparing for a long contest in which neither can deliver a knockout. Democrats can use hearings, subpoenas, document demands and public testimony to change what Americans know about how enforcement has been carried out, and that could shift public opinion further. They can shape future budgets at the margins. What they cannot do, on the current law and the current calendar, is switch off a deportation programme that has been funded in advance and is directed by a White House determined to continue it.
For voters, the practical test over the next year will be whether oversight produces specific findings, on spending, hiring standards, detention conditions or the treatment of citizens, rather than slogans. For the administration, the test is whether Miller's promotion is read as resolve or as a refusal to hear the election. Both sides now have the tools to make their case. Only one of them has the money already in the bank.