hmm, I cant speak for anyone else's experience, but i just finished my undergrad in music performance and international affairs(from a conservatory/university), and am heading to a reputable MA program for curatorial practice(yes different, but maybe still applicable) this fall.
The program just made sure to supply me with an art history reading list for me to read over the summer. If you can demonstrate strong methods/research bridging politics and art, that will be super helpful. Coming from a different field will definitely put you at a slight disadvantage, but don't count yourself out yet. Also have a strong writing sample or two relating art and politics(or just art tbh). Just show that you're actively putting in a lot of effort to redirect yourself and career.