One of the frustrations of Congressional races is the lack of good publicly-available polling. Kuhl and Massa probably have great internal polls that tell them how they're doing precinct-by-precinct. The general public has to make do with vague national polls and the crumbs that the campaigns want to throw us.
The last poll that I've seen for this race is a four months old. It showed the race at a statistical dead heat, and Randy's negatives at 50%. It was produced by Massa's campaign, so caveat emptor, but it's the freshest crumb we have.