If your goal is to signal that you despise that party, then by all means keep using it here, but it seems closer to the kind of substantive discourse that HN encourages to avoid it.
To me the -an suffix on Republican seems to suggest the word is about a person where as the word Democratic seems like it is an adjective so Democrat in my mind just gives it a more personified feel.
Conservatives may use Democrat derogatorily but it's still a useful term and in my opinion shouldn't be banned outright from discourse. Maybe I'm missing the context you were speaking of though.