“Republicans’ former arguments about the specter of big government were too vague and out there; now it’s something that’s very concrete,” said Soltis.

Millennials, Soltis argued, care about results, not ideology. “That’s the power here. Rather than being an esoteric philosophical argument about big government, this is now concrete, you can see it on your screen.”

Republicans also are counting on the way the exchanges are delivered, online, to help them. People who matured in the iPhone and Facebook age have little patience for technical mistakes, especially if they last for weeks or months.

“The president did himself a disservice when he started comparing the rollout of Obamacare to products that young Millennials know, like Apple and Kayak,” said Raffi Williams, a spokesman for the Republican National Committee who specializes in youth outreach. “It gave them something firm to compare it to. They think, ‘I use these products every day and they’re terrific.’ Whereas with Obamacare and the exchanges, they’re not working at all.”