Maybe the Fourth Duke of Wellington who was a Fascist Sympathiser and a BUF member could get into politics, although I'm not sure how.When I wrote about a hardliner getting into power, I meant politically. Fuller was only "involved with fascists" after his military career ended. He also turned down Command at Tidworth in '27 to concentrate on his mechanised warfare theories, so would be unlikely to enter politics before that.
Also I've thought of another POD that is before 1900 but could help, Albert Victor doesn't die in 1892 and is still alive when Edward the VII dies. He still acts like his father having parties, sleeping around and acting foolish even has the war goes on alienating his subjects. Maybe he has more conservative views than his father.
King George V with his rather more modest and unassuming behaviour made him more relatable to the people of Britian during and after the War (particularly the middle class). Albert could possibly anger the working and middle classes if he acted like a fool.