Exhibit A might be the rigid racial, ethnic, and gender quota systems that Democrats have maintained for selecting delegates to their national convention ever since the McGovern convention in 1972. Since there is hardly a more important function for a national party than choosing (and supporting) a presidential candidate by these delegates, this is very strong evidence of the Democrats' internal thinking on racial, ethnic, and gender matters. And their general support for racial quotas throughout American society would be Exhibit B.
I don't capitalize either party's name because I do not respect them enough to do so. Same with the senate and senators.