Saying upfront that you typically support the opposite side doesn't give your argument more validity.

We've ALL seen these comments...

"As someone who voted for (other party), I think this admin is doing fine."

"As a dog owner, I think cats are better."

"As someone who wrestled in high school, I think boxing is better."

"Coming from someone that usually hates noisy neighbors, this wasn't that bad."

Saying that stuff doesn't give you more credibility or your stance more validity. Support it with evidence and why or don't say it at all. The only time when you SHOULD say it is if you're listing credentials. "As a dentist, I do not recommend only brushing once."