I'm in Canada, and I think the term used here is 'rejected ballots' or 'declined ballots'

Some links:

• https://www.cbc.ca/news/canada/kitchener-waterloo/ontario-votes-2022-declined-ballots-rise-1.6466308
• https://www.elections.ca/content.aspx?section=vot&dir=bkg&document=ec90565&lang=e

The first article is specifically the effect I described, where people report the number of declined ballots, interview people who chose to do that, and talk about why it might be happening. That has an impact, but the magnitude depends on how prolific it is.

Second link quoted:

Ballots must be rejected if they were not supplied by an election officer, were improperly marked (including those voided by the elector), were cast for a person other than a candidate, or if there is any writing or mark by which the elector could be identified.

After the count, the election officer fills out a statement of the vote, recording the number of votes in favour of each candidate and the number of rejected ballots. In this statement, the election officer has to account for all ballots received at that poll.

I'm not as familiar with the US. My point was a blank ballot can have a different outcome from not showing up, and it can be a valid strategy depending on where you are in the world.

You are talking out of your ass. They know who voted, what party they are affiliated with. They don’t know who voted for who.