While this is a shit move by whoever is doing this, it makes virtually no difference for the presidential election. WA electoral votes are winner-takes-all, and always go Dem. A few burned boxes won’t come close in making a difference for president, Biden won by almost a million votes in the last one. It will probably have a decent effect on local elections though.

I honestly wouldn’t be surprised if there was a political bias between people who are and aren’t willing to answer phone calls and participate in polls.