Nossir. The phrase must be "I'm a Deplorable!".
"Deplorable" is an adjective, and it is derogatory.
"A Deplorable" is a noun, and is a member of the group, "The Deplorables".
I forget the exact quote and cannot find it, but a German general in WWI said, "Let us roll over the French outcasts!" and the French adopted the phrase as their own, naming a battle group "The Outcasts" or some such similar thing.
We should do the same.
You’re irredeemable it’s Teufelshunde!