Political labels are a box. Why do people put themselves in a box? Does it make them feel safe? Is it so they can generalize and pretend they have it all figured out.
Do you believe what you believed 10 years ago? 5 years ago?
Has your beliefs not grown and changed? Was new evidence not introduced that changed what you believe enough for you to put yourself under a different political label?
Oh, everyone else is labeling themselves too... must conform or label myself a nonconformist.
Labels bind you. You're telling people what you believe and it creates a fixed self-image that you're socially pressured to maintain - Willfully enhancing your cognitive bias by tying it to your own self worth.