Causality/Correlation

These lines from this very good Matt Stoller piece stood out as obvious but also very important and often misunderstood:

The only time the question even comes up now is in an inverted corroded form, when a liberal activist gnashes his or her teeth and wonders — why can’t Democrats run elections around populist themes and policies? This is still the wrong question, because it assumes the wrong causality. Parties don’t poll for good ideas, run races on them, and then govern. They have ideas, poll to find out how to sell those ideas, and run races and recruit candidates based on the polling. It’s ideas first, then the sales pitch. If the sales pitch is bad, it’s often the best of what can be made of an unpopular stew of ideas.