Just six months out from the midterms, Democrats increasingly fear they’ll fail to renew those generous subsidies, which expire at the end of the year, triggering sudden spikes in insurance premiums and wiping out one of Biden’s signature health care accomplishments.

The price hikes would hit an estimated 13 million people across the country, potentially adding hundreds of dollars to families’ monthly expenses. And in a painful twist for a White House already struggling to contain anger over rising household costs, voters would begin receiving notices about their premium increases in October — around the same time they’re starting to cast their midterm ballots.

“It’s not a good look when you’re going into a midterm election,” said Sabrina Corlette, co-director of the Center on Health Insurance Reforms at Georgetown University’s McCourt School of Public Policy. “There could be some really awful stories about people losing coverage.”

The scenario has alarmed vulnerable lawmakers and White House allies, who have privately warned senior Democrats in recent weeks that the issue could cost Democrats control of the Senate and decimate their hard-earned reputation as the party of health care.