My husband, John (also a sociologist), was quite disturbed recently when he heard several conservative commentators/politicians use the phrase "Democrat Party." He thought that the speakers were merely ignorant of proper grammar. "Democrat" is a noun, and should not be used to modify another noun "party" - nouns are modified by adjectives such as "Democratic."
I explained to him that, while the phrase might be grammatically incorrect, that the speakers were making the statement not out of ignorance but rather from a deliberate decision to denigrate the Democratic Party. I don't think he quite believed me, until I found the Wikipedia entry on "Democrat Party(phrase)." However, even I was surprised to discover how long a political history the phrase has. The first recorded use goes back to 1890, but it became a commonly used epithet by Republicans in the 1930's and 1940's. Harold Stassen made the derogatory nature of the label clear in a 1940 statement in which he argued that because of the prevalence of political machines in larger urban areas such as Chicago and New Jersey, the party no longer deserved to be called "democratic."
Grammar, like vocabulary, is not static, but evolves over time, to meet the needs of a living culture. The use of phrases like "Democrat Party" serve a political purpose, and in using them, people contribute to changes in the language as well as subtly affecting perceptions of their listeners.
A different example of changing grammatical usage, the phrase "well paying job." Today one finds that references "well paying jobs" and "well-paying jobs" (226,000 Google entries) some what outnumber references to "good paying jobs" (169,000 entries). Thirty to forty years ago, the reverse was true, and "good paying" was more likely to be heard.
Searching the Internet one finds that arguments for the grammatical correctness of both phrases. The arguments vary. "Good" is an adjective, while in some instances "well" is an adjective also, "well" is more often an adverb. The word paying is a "present participle," a word that can act either as a verb (he is paying her a salary) or as an adjective (a paying job as opposed to one without pay).
Grammar books say that adjectives modify nouns only, while adverbs modify adjectives, adverbs, and verbs. That would suggest that "well paying" is more grammatically correct than "good paying." However, there some that argue that both "good" and "paying" modify "job" (as in "good job" and "paying job" and so both should be adjectives.
There seems to be little difference in the types of websites that use these phrases, both are found on University websites, both are found in newspapers and magazine articles, both are found on websites of organizations and government agencies.
Microsoft, in the Word grammar checker has taken a neutral position: "well-paying," "well paying," "good-paying," and "good paying" are pass inspection by the grammar checker. But that may not be saying much. The grammar checker did not flag "This is a good paid job. " Although it did flag "This job is paid good" as ungrammatical.
The point, there appears to be no agreed upon, clear grammatical reason for choosing "well paying" versus "good paying," but current social conventions appear to slightly prefer "well paying," while the phrase "good paying" was more commonly used in the past.
Language and its grammar is a living, breathing, changing entity.