If you want a good indication as to how the major party presidential candidates are doing, pay attention to where they are campaigning. Candidates have access to the most reliable private polling. This is beyond the polling that we, the general public, see in media reports. Since Richard Nixon promised to campaign in all 50 states in his unsuccessful run for president in 1960, candidates have learned to focus on swing states and not waste their energy on the deep red or deep blue states.
When a candidate holds a public campaign event, it's for two possible reasons: either they were ahead in a state they need but have detected an erosion of support which they want to counteract, or it is a state in which they were behind but now see they have a shot at winning. In other words, there is much to be inferred if a candidate is playing offense or defense.
On a similar note, there is much to be gleaned as to where the campaigns are running ads. In very blue Oregon, I have yet to see presidential campaign ad appearing locally. I wouldn't be surprised if Ponderer, Donna and HtS have seen campaign ads in Arizona and Pennsylvania respectively.
Kamala Harris just appeared in Wisconsin and will be in Indiana today. Trump will be rallying in North Carolina.