With the government shutdown well into its second week, President Donald Trump’s strategy to break Senate Democrats has become clear: Maximize the pain of the closure to force them into retreat. His administration is firing civil servants en masse, threatening to withhold back pay from furloughed federal employees, and canceling billions of dollars in funding for states that voted for his opponent last year.

Yet with only a couple of exceptions, the party’s senators are holding firm—to the unexpected delight of House Democrats worried that their counterparts across the Capitol, whose votes are needed to reopen the government, might cave in the face of Trump’s heavy-handed pressure campaign. “I’m surprised, but I’m happy,” Representative Eric Swalwell told us. Like many of his House colleagues, the California Democrat had been bitterly frustrated when Senate Minority Leader Chuck Schumer surrendered the last spending fight in March, making the current shutdown nearly a forgone conclusion.

Far from folding, Senate Democrats appear to be unusually united and even more emboldened with each passing day the government remains closed. They haven’t budged from their insistence that, before they will vote to end the shutdown, Republicans first must agree to extend health-insurance subsidies that are due to expire at the end of the year.