The upcoming US mid-term elections could change which political party controls Congress, which meets in the US Capitol building in Washington DC.Credit: Finn Gomez/GettyAs tens of millions of voters head to the polls on 3 November to cast ballots in the US mid-term elections, a political shake-up could be coming to Washington DC — with substantial consequences for the country’s scientific landscape.Republicans currently hold more seats than do Democrats in both chambers of the US Congress, which has given the party and administration of President Donald Trump unified control of the federal government. But polling data favour Democrats to win back the House of Representatives and suggest that they have a chance of taking control of the Senate, too.Since Trump took office last year, his administration has terminated thousands of research grants, slashed the federal scientific workforce and sought unprecedented political oversight of science agencies such as the US National Institutes of Health (NIH) and the US National Science Foundation (NSF). Many researchers and science advocates hope that a new Congress will stand up to the Trump administration to protect science funding and investigate its actions. “The Republican Congress has basically ceded their role in oversight for the last almost two years,” says Shaughnessy Naughton, president of 314 Action, a political fundraising group in Washington DC, which recruits and backs Democratic scientists, engineers and health-care specialists running for office.Funding fightThe Trump administration has requested deep cuts to federal science budgets for the past couple of years, asking for the NSF’s budget, for example, to be cut by more than 50% in fiscal years 2026 and 2027. Both Republican and Democratic members of Congress, which sets the federal budget, have staved off those cuts so far. But the budget for the 2027 fiscal year, which began on 1 October, has not yet been officially approved.White House proposes vast overhaul of US science funding: what you need to knowEven if Democrats, who have been backing boosts in science spending, were to win control of both chambers of Congress, it could be difficult to push through any major funding increases, because the final budget bills must still be signed by Trump.At a minimum, researchers and science advocates hope that Congress will continue to prevent big budget cuts. But keeping budgets steady on paper has not stopped the administration from squeezing research in practice. Without congressional approval, the White House has curbed spending in other ways — terminating active grants mid-cycle and refusing to distribute money that Congress had already approved, a controversial tactic known as impoundment.Science advocates say they hope that a new Congress will assert its budgetary power, namely by pushing back on these actions. The NSF, for instance, closed the 2026 fiscal year on 30 September with some US$1.4 billion in unspent funds, leading to the lowest number of new research grants issued in decades. The agency said that it has two years by law to spend its approved budget.The Government Accountability Office (GAO), the investigative arm of Congress that has the ability to determine whether funds have been impounded, has rarely pursued action over violations, says Matt Dull, a specialist in government oversight at Virginia Tech, in Blacksburg, but the mid-terms could change the situation.Controversial White House plan to overhaul US science funding faces Senate oppositionAnother way that Congress could push back against the Trump administration’s reshaping of US science is to attach specific conditions to funding bills. For instance, because lawmakers haven’t yet agreed on the final budget for the 2027 fiscal year, they passed a ‘stopgap’ bill that funds the government only up to 11 December. The bill contains a section that temporarily blocks a White House plan to overhaul US science.That plan is controversial: it would, for instance, put political appointees in charge of federal grant review and allow them to override the decisions of scientist peer reviewers. Giving control of grants to political appointees would threaten biomedical progress globally, says Ellie Dehoney, senior vice-president of policy and advocacy at Research!America, a non-profit organization in Arlington, Virginia. The White House Office of Management and Budget (OMB), which created the plan, said it did so to improve transparency, accountability and oversight of federal funds.Rosa DeLauro, a Democratic representative from Connecticut, issued a statement last month saying that she was confident that Congress would continue blocking the OMB plan in future spending bills.Increased oversightAlthough Congress does not run US science agencies, it has oversight powers, which include launching investigations into agency actions. Most of these powers are reserved for the party in control of Congress, and Democrats have pledged to use them if they win big in the mid-terms.‘Science needs defending’: record number of researchers run for office in US mid-terms“We will continue the work we have been doing over the past two years to hold the Trump administration accountable,” says Zoe Lofgren, the most senior Democrat on the House Science, Space and Technology (SST) Committee. “If we win, we’ll have more tools at our disposal to do exactly that.” Lofgren and her Democratic colleagues have sent numerous letters to agencies such as the NSF and the US Department of Energy asking about actions such as grant terminations but have received few answers. If Democrats take control, Lofgren, who represents a California district and could become head of the SST committee, would have the ability to issue subpoenas, which can be used to compel administrators to testify in front of Congress.