Persuasion
There are very few people who are willing or able to be persuaded. Too many cross their arms and say, “don’t confuse me with facts, my mind is made up”.
If you do run across someone who can be persuaded, simply ask them for their three biggest issues in the upcoming election and then ask who they think will be best at addressing those issues. Let them decide for themselves. If they are so blinded by ideology, giving them statistics, etc won’t matter.