If it were me in this position, I would definitely do a double major. One of them would have to be political sciences an obvious choice for someone interested in politics. Then I’d have to think what else would be good for me to show I have what it takes to communicate and write speeches. Then I’d see well if I’m really good at writing papers, have aced my way through English classes and have an extreme talent I would say well can I do better at English or could I learn more with communication skills? I’d also consider what politicians look for in a speech writer, well most look for candidates with English degrees. So they look for English degrees, I’m very strong at English but I can always improve anyone can improve on English. So I’d pick a double major in political science and English.