More than 30 minutes into the three-hour debate, Kamala Harris made a undeniable point: “This discussion is giving Americans a headache.”

The moderators and planners of the debate got something wrong right off the bat: Opening things up with a lengthy and contentious discussion of health care. While it’s a hugely important issue, it is not the only issue. Health care was also the lead-off topic of the two earlier Democratic debates, and the discussion was very similar. If any really new ground was plowed, I doubt it was obvious to any but serious health-care wonks. And they have probably already made up their minds on this issue.

It wasn’t until 8:40 p.m. that the discussion moved on to another topic. Many viewers who tuned in at the beginning of the debate surely were reaching for their headache medication — prescription or otherwise — by then. It was a tactical error on the part of ABC’s planners.