Dear Tenacious0,
I am merely stating that the Civil Rights Act of 1964 does not protect folks against discrimination based on political preferences. Period.
That being said, if Ms. Goldberg walked into a restaurant and was refused service based on her politics, she could not sue for discrimination based on political discrimination.
However, if she were to demonstrate that screening people on the basis of their political affiliation had a significant adverse effect on a "protected class" (such as black people), then she could sue for racial discrimination, basing her claim on the theory of "disparate impact."
In the employment law field, generally speaking, there is a prima facie case made for discrimination if the "four-fifths" rule is violated. That is, if the effect of the screen has the effect of causing members of the "protected group" to have less than 80% of the representation they otherwise might have if represented proportionately to the population from which the employer usually draws. Then the burden of proof falls to the defendant to prove he has not discriminated.
Thus, it is likely that Ms. Goldberg would at least have a case, since the overwhelming majority of black people vote Democrat, and if the screen were to be applied across-the-board, if would disproportionately affect black people very severely.
However, the Bush twins likely could not make a claim, as discriminating against Republicans will not generally disproportionately harm members of any "protected class."
Even if one makes a claim based on discrimination against white people, the fact is that a large minority of white folks are Democrats, and thus, it would be difficult that if the screen were universally applied that it would have a disproportionate adverse impact on white people.
Hope that makes it clearer.
sitetest
A lot of cities have their own civil rights laws which are broader than federal law, and political affiliation is often a protected category in those cities.