To rail against something is to complain about it bitterly and at length. Loud, sustained, and rarely productive.
It takes a direct object after against. The word is formal and slightly literary, and it appears in descriptions of columnists, preachers and anybody who has been complaining for years about the same thing. There is a suggestion of futility built in, since railing against something implies nothing will change. The verb rail here has nothing to do with railways and comes from an old French word for mockery.
1phraserail againstTo complain bitterly and at length about something.
“He would rail against the council at every opportunity.”