Someone actually did make soundbanks based on syllables/morae from Trump and Sanders speeches, for the freeware (sadly not open-source) version of Vocaloid [1]. While it is technically extremely difficult to use this technology to approximate English speech (which has a much wider array of possible phonemes than Japanese), the soundbanks can already "cover" some of the more famous Japanese Vocaloid songs [2].

[1] https://en.wikipedia.org/wiki/Utau - which incidentally was the software that created the voice for that erstwhile Nyan Cat meme

[2] http://store.vocallective.net/album/trumploid-vs-sanderpoid-...