A little off the point of the post, but this is a curious turn of phrase. Laski, btw, was at the philosophical core of the militant Labour movement in the UK immediately post-war. It was his ilk that nearly drove the UK to destruction (on the same course as the French are currently on). Perpetual strikes, work stoppages and job actions brought the country to the verge of dissolution 'til Thatcher set things right.
Nothing curious at all. It may be impossible for Americans to underatand, but in monarchies the idea of a republic attracts progressive intellectuals and radicals.