We don't hear much about the former nowadays; there are still plenty of the latter around, and we can learn their views in some newspapers and on many websites.
Here are some edited extracts from the OED:
blackguard: The origin is from black guard. It is possible that senses 1 and 2 began independently of each other; or the one may have originated in a play upon the other, black being taken with a different sense. It is even possible that there may have been a guard of soldiers at Westminster called the Black Guard, or that, as some suggest, the attendants or torch-bearers at a funeral, or the link-boys of the streets, may have had this name.
1. The lowest menials of a royal or noble household, who had charge of pots and pans and other kitchen utensils, and rode in the wagons conveying these during journeys from one residence to another; the scullions and kitchen-knaves.
2. A guard of attendants, black in person, dress, or character; a following of ‘black’ villains.
3. One of the idle criminal class; a ‘rough’; hence, a low worthless character addicted to or ready for crime; an open scoundrel. (A term of the utmost opprobrium.)
4. Of or pertaining to the dregs of the community; of low, worthless character; brutally vicious or scurrilous.
All these meanings are obsolete except the last, which is a period piece rarely used except as a joke: "You're a blackguard, sir!" (Compare: "The fellow's a mountebank!")
Middle French bigot, person who shows excessive religious zeal, a religious hypocrite, (15th cent.), of uncertain origin, perhaps ultimately from either English by God or an equivalent expression in another Germanic language (although there is apparently no evidence for this supposition). It is uncertain whether the Middle French word shows a direct connection with Old French bigot, attested in the 12th cent. as an offensive name given to the Normans.
1. A religious hypocrite; (also) a superstitious adherent of religion. Obs.
2. A person considered to adhere unreasonably or obstinately to a particular religious belief, practice, etc.
3. In extended use: a fanatical adherent or believer; a person characterized by obstinate, intolerant, or strongly partisan beliefs.