I came up with a pretty good one I think

All Darth Vader did was help Palpatine build the Death Star, and it was Tarkin who actually gave the order. Do these anti-Vader people even understand what his role is as Sith Lord?

These single-issue voters who refuse to vote for Vader just because of the Aderaan issue are just helping Palpatine. Why does everyone suddenly care so much about Alderaan anyway?