Reason No. 5: The Russia investigation isn’t a big priority for voters.

In addition to not seeing the Barr letter as hugely informative, most of the public didn’t care that much about Russia in the first place. A Gallup poll taken in October 2018 in advance of the midterms found that the Russia investigation ranked last in importance among 12 issues that Gallup asked about, with 45 percent of voters saying it was very important or extremely important to their vote for Congress. By comparison, 80 percent of voters said that about health care, the top-ranked issue.

Views on the importance of Russiagate were highly partisan: 66 percent of Democrats2said it was very or extremely important, as compared to just 19 percent of Republicans.3 That helps to explain why Russia got so much coverage on MSNBC and CNN, which have largely Democratic audiences. At the same time, if (a) only partisan Democrats cared very much about Russia and (b) those Democrats have plenty of other reasons to dislike Trump anyway and (c) they aren’t likely to be persuaded by the Barr letter besides that, you can see why the end of the investigation hasn’t moved the needle much in terms of Trump’s overall approval.