I think it was from the 1980s. Main characters were twins, man and woman, where the woman had psychic powers and embraced the community of others with talents. Whereas the man was the opposite and used his political powers to fight that community - only to realize in the end that he too had powers which enabled him to advance his career in politics. Hope this site can help me jog my memory. :)
The Tales of the Continuing Time, three novels of which (Emerald Eyes, The Long Run, The Last Dancer) were published in the late 1980s and early 1990s by Daniel Keys Moran.
I've read the first and the last of the three novels and The Last Dancer does feature two twin telepaths.
In Marion Zimmer Bradley's Darkover series, Leonie and Lorrill Hastur are twins in (one of) the highest ranking family on the planet. She is the stronger telepath and undergoes rigorous training which in the end brings her to the most powerful position in the "Towers", where psychic powers are trained and used. Lorill goes on to be the Regent for Prince Aran Elhalyn, and basically the ruler.
"Rediscovery", in which they are young and just beginning, and are main characters, is published a little late for your description, but the two appear in other books as well, such as "The Forbidden Tower".
This is a bit of a long shot, as they are rarely the main characters in the books in which they appear, and I do not remember him fighting against the Towers.