I love how the same people who take every Democratic-friendly poll and even Democratic internals at face value always rush to remind us that (R)emington is basically just cooking up R-friendly numbers and shouldn’t be trusted, even though their final poll in 2016 actually underestimated Greitens and Trump significantly. But sure, go ahead and underestimate McCaskill's (or Heitkamp's, Tester's, and Donnelly's) vulnerability to your heart's content, I’m sure it’s just Republicans being overconfident again.
I honestly don't see people take Democrat internals at face value. This is an R leaning polling outfit that has consistently shown Hawley ahead by 2-4 points. I don't think anyone is underestimating McCaskill's vulnerability - this is a pure tossup.
