In Nevada (not trusting the mail in vote) I’ll be voting early on a voting machine that consists of a touch screen and a paper scroll records the vote on paper behind a transparent screen. There is literally no way to vote for Bernie, (unless I use the mail in ballot, which again I won’t trust). And I’m not sure that such markings on a ballot won’t invalidate all down ballot choices such as your choice for the U.S. House of Representatives, etc. How do you know that your ballot does not go directly into the trash because of the stray marks?
Incidentally, Nevada has a choice of “None of these Candidates” on the Presidential election. I’ll vote tomorrow. “None of these Candidates” will most likely be my choice, unless of course Joe Biden came out tonight and promised that if M4A passed the Congress, he would sign it into law or something like that.