“Democrats need to have a positive agenda, not just be against Donald Trump.” How many times did you hear pundits say something like that during the midterm campaigns? In fact, you’re still hearing it from people like Seth Moulton, who’s leading the (apparently failing) effort to block Nancy Pelosi from returning as House speaker.

What makes this lazy accusation so annoying is that it’s demonstrably, arithmetically wrong. Yes, Trump was on everyone’s mind, but he was remarkably absent from Democratic messaging. A tally by the Wesleyan Media Project found that the 2018 elections stand out not for how much Democrats talked about the tweeter in chief, but for how little: Not since 2002 has an opposition party run so few ads attacking the occupant of the White House.

So what did the campaigns that led to a blue wave talk about? Above all, health care, which featured in more than half of Democrats’ ads. Which raises the question: Now that Democrats have had their big House victory and a lot of success in state-level races, can they do anything to deliver on their key campaign issue?

Yes, they can.

Actually, just by capturing the House Democrats achieved one big goal — taking repeal of the Affordable Care Act off the table. True, the G.O.P. lawsuit against the act’s protection of pre-existing conditions is still awaiting a ruling — the long silence of the Republican-leaning judge in that case is getting increasingly strange. But there won’t be any more legislative attempts to dismantle the law.