The 2020 election is still two and a half years away, but the Big Sneer is already underway. Name a potential Democratic candidate, and you know how pundits will react: the same way they reacted to Al Gore and Hillary Clinton. He/she (especially she), they’ll say, is tired, boring, annoying. Above all, they’ll complain, he/she doesn’t offer any new ideas.

Somehow it’s always Democrats who get this kind of criticism, even though every prominent Republican for the past three decades has espoused the same three bad ideas: tax cuts for the rich, slashed benefits for the poor, and more pollution. Paul Ryan 2010 was basically Newt Gingrich 1995 with a lower BMI, yet he got praised endlessly as an innovative thinker.

But let’s leave the asymmetric treatment of the parties aside, and ask a simple question: why, exactly, do we demand that politicians have new ideas?

I’m not saying that politicians shouldn’t be open to new thinking and evidence about policy. But a political party isn’t like Apple, which needs to keep coming up with glitzier products to stay ahead of Android. There are huge problems with U.S. policy on many fronts, but very few of these problems come from lack of good new ideas. They come, instead, from failure to act on what we already know – and, for the most part, have known for a long time.