Midterm elections could jolt stocks as Democrats look poised to sweep Congress

Investors were not positioned for a Democratic sweep of Congress heading into Tuesday's midterm elections, according to CNBC. The report says the political climate could be a headwind for stocks into year-end.

Tobin Marcus, head of U.S. policy and politics at Wolfe Research, said investors show "begrudging acceptance" of a likely Democratic sweep. His firm's survey of more than 100 institutional investors found they are not strongly positioned for any particular result. Marcus said Wolfe shares the view that "polling is likely overstating Democratic strength."

JPMorgan expects a blue wave to push the S&P 500 down about half a percent on Wednesday. Overnight futures pointed to larger losses. The report says a Republican hold on both chambers could spur a rally, and that a Republican hold of the Senate alone could be "a tailwind for equities into year-end," according to Citigroup strategists.

Jonathan Krinsky, chief market technician at BTIG, wrote that the S&P 500 has typically averaged a 14% drawdown in the second half of midterm years. He said the usual pattern of weakness before elections and strength after them may not hold this year, because the index has already posted double-digit gains in 2026.

The report says a strong Democratic showing could add pressure to artificial intelligence stocks, which have already been volatile. Analysts quoted by CNBC said increased Democratic control at the state level would likely weigh on stocks tied to data centers and technology capital equipment. Rob Rains of Washington Analysis said it would "solidify" early cautionary signs about AI infrastructure in several states. Goldman Sachs strategists said a Democratic Conger "might limit data center tax incentives, but a national moratorium looks unlikely in any election outcome."

CNBC reports that a surprise loss by Republican Gov. Greg Abbott in Texas could unsettle the market in the short term, according to Marcus.

Alex Sagal of Wells Fargo Investment Institute said a substantial Democratic sweep could limit real defense spending growth unless a broader deal raises defense and health care funding. He described the defense earnings outlook as "stable to modestly positive."

Healthcare stocks could benefit. Marcus said Democrats will likely push to restore expired Affordable Care Act enhanced premium subsidies or unwind some Medicaid reforms in the One Big Beautiful Bill Act. Jed Ellerbroek of Argent Capital Management said he is watching hospital operators such as HCA Healthcare and Tenet Healthcare, and insurers such as UnitedHealth and Centene.

Financials were the weakest S&P 500 sector early in 2026, after President Donald Trump called on Congress to cap credit card interest rates at 10%. The sector is up about 3% so far this year. Matthew Aks of Evercore ISI said Democrats will likely target consumer-facing sectors to show progress on affordability, which could add instability for financial stocks.