Political writing has a default mood. A vaporous pessimism, with windily non-specific warnings about the future is, I find, the safest tack. Folks rarely get fired for being too bleak because modern political societies have a constant need for adjustment and warning. In our fallen democratic condition, the grief of recent failure can be intense. Bland Cassandras are à la mode. But after recent events we must admit the unthinkable: our local systems are working. Parliamentary democracy is redeeming itself. At Westminster, a rule-breaking populism has been expelled. In Edinburgh, a democracy that was subsiding into a one-party, top-down system...