Fair or not, here is the reality when it comes to these celebrity endorsements IMO: it turns off the average voter more than it helps. No one thinks it's authentic, fair or not. Many believe the endorsement is based purely on the party affiliation, not the candidate. That these types of endorsements are driven by group-think, signifying so-called virtue and to be asked to the next cocktail party or sit at the proverbial "cool kids" table. I'm not sure how much it helps, and for every voter it actually impacts there are probably several it makes want to do the opposite.