3. The most easily persuaded pay the least attention
Although partisanship and partisan messaging locked most Americans into their views before the hearings, a sizable minority were undecided on impeachment.
Public opinion is often difficult to change precisely because the most easily persuaded people pay the least attention to the news. This was certainly true for the impeachment hearings.
In two separate polls — one conducted after the first day of the impeachment hearings and the second fielded after the Intelligence Committee hearings ended — YouGov/HuffPost asked its respondents how closely they were following the impeachment proceedings.