seemingly because Trump supported vaccines but
not masks.
I read both conservative and liberal media and have never seen it suggested that masks were somehow better than vaccines.
First I must strongly state that the idea itself makes no sense: one can wear a mask and be vaccinated; they're not competing ideas in any meaningful way.
However, at the outset of COVID-19, we certainly were not sure that there would be effective vaccines, or how long they might take to develop, or what their supply levels would be.
Therefore it made sense to take whatever (effective) measures we could, while waiting for a vaccine that was never guaranteed to exist. Nobody argues that a fire extinguisher is better than a squad of professional firefighters, but fire extinguishers can have important utility, especially while you're waiting for help to arrive.
As far as the Trump angle, perhaps you can show us a counter example, but I have seen zero evidence that anti-Trump folks have rejected vaccines because Trump favored them. It's a non-factor.
One, the liberal/progressive/whatever crowd is overwhelmingly pro-vaccination (in general) to begin with. Two, and perhaps more importantly, they're just not competing with masks in any way. Masks are imperfect; vaccines are more effective but also imperfect and not approved for all people even today. That is how you deal with many if not most threats in the real world: multiple layers of imperfect defences.