Finding an organized group that is trying (through activism or voting or both) to influence policy is probably an even better way. Ralph Nader wrote a great article about this and he has a significant history of achieving wins like the creation of OSHA and FOIA -- basically in short summary, he recommended forming a coalition which will only vote for a particular leader if that leader will commit to some concession to humanity that you're trying to achieve. Then, communicating that to the leader in a credible fashion to put pressure on them. It takes a ton more effort and it's not guaranteed to work, and you have to get out of your house and find other people who feel the same way. But it does actually produce tangible results. Just leaving the box blank will either do nothing or produce a catastrophically worse result; there is no possible way that it can help in any capacity.