And even if only one party was called out, it doesn't mean its partisan. Not all opinions deserve equal weight. If someone started the Anti-Science Party and said the Earth was flat and only 7 years old, it wouldn't be partisan to say they're insane and you wouldn't want them in charge of important decisions, it would just be that this one party happens to be even more insane than the rest and you're calling them on it. The other party might believe the Earth is only 6000 years old, but fact remains that this hypothetical Anti-Science Party is basing their entire campaign on their belief rather than their understanding.

Playing the partisan card is just deflection to avoid the realization that some things simply cannot be argued seriously in a respectable conversation. Pointing the finger and saying "they do it too!" doesn't make your side any better.