The far-right has been a powerhouse with "messaging" - they cornered and made sure to paint themselves as the true patriots, lovers of freedom, and yes - flag-loving-they-are-the-only-ones-who-really-love America citizens.
In the last 10 years that I lived in the US - I did identify flag-flying homes in the "burbs" as Republicans (which is wrong - many on the left fly their flags)
...then in the last years, I associated it with Trump supporters once they coupled it with the police flags (I think it's the one with blue or black stripes?...not sure)
I'm sorry your outfit was misjudged - it's lovely! And I'm glad you are celebrating this day in honor of many whom we should be thankful for...as your dad and grandfather.
Thanks for posting this - thanks for speaking out on the beauty and true symbolism of the American flag.
Happy Memorial Day!