The doubt in you, I sense. Polls may be done poorly, however this poll was conducted by both NBC News and the Wall Street Journal--not always known for being in lockstep. The margin of error was +/- 4.9-5.5%, wider than some, but narrow enough when dealing with these pretty straightforward questions, and the broad disparity between the two party affiliates. Honestly, that there is even any difference at all is problematic, as an epidemic doesn't take politics into account.

Here's a good article on polls by one of the premier polling organizations.
[pewresearch.org]

@p-nullifidian Doubt indeed. I try hard to fight it, but have gotten burned too many times before. I agree, epidemics/pandemics have zero regard for human politics.