Conservative and Liberal are opposite poles of a continuous political spectrum, they are directions, not locations. It doesn't really mean there are two opposed ways to look at every issue, just that there is a gradient of opinion and one direction is to the Right, the other to the Left.

Furthermore, there is no reason why having a position on one issue should mean embracing the Party position on all issues. It is perfectly reasonable for a person to be a Financial Conservative and simultaneously a Social Liberal--or vice-versa. In all the major issues which divide American society, there is no reason why we should obediently line up by Party. I, for example, consider myself a defense hawk, a law-and-order Conservative, a traditionalist when it comes to education, and have very Right Wing opinions on immigration (but for very different reasons!) and a Liberal on social, welfare, environmental, racial and Labour questions.

It has always been this way, historically. Remember when the Abolitionists were all fundamentalist Christians? Or when Anti-war sentiment was strong in the mainstream Churches? Or when the Federalist founders were all deists?

But somewhere along the line, this changed. Before long, it became the case that when you learned somebody's opinion on one issue, you could make a very good guess on what their positions were on every other issue. I have very clear and consistent ideas on why this has become the case, but I haven't any interest in starting yet another pointless argument. Let it be said that we now have an approved list of positions on every question which are assigned to each side of the political spectrum.

You're right. Modern Conservatives have an utter contempt for Liberals. In fact, that seems to be their single most unifying characteristic. Although it is inevitable that contempt should eventually flow in both directions it is my own admittedly partisan opinion that this is due to Conservatives, not Liberals. Again, I will not engage in any pointless arguments why, but that's my story and I'm sticking to it. And I don't believe this Left-flowing antipathy is due to any complex social, historical or political forces. No, I think it is deliberate political organizing strategy on the part of the Right. It doesn't have to be this way, it wasn't always this way, but that's the way it is now and I think its (mostly) on them. And they did it on purpose, in order to get votes.

You can vaguely trace the origins of this pattern historically, from Civil War, Reconstruction, the Gilded Age, through the New Deal. But it becomes really noticeable after the arrival of McCarthyism, then Goldwater, the John Birch Society, and finally in its modern, most virulent form, with Segregation, Nixon's Southern Strategy, Reagan, Libertarianism the TParty and finally, Trump.

The single key organizing principle is race. No, the relationship is not one-to-one, it is subtle and convoluted, the origins are economic, but the battle fronts have been re-drawn along pre-existing racial fault lines. And those battle lines were consciously and deliberately manipulated for political, and economic reasons. Basically, racial conflict has been used to define political position, rather than economic class. The distinction has since become blurred and confused, since there IS considerable class mobility, both racial and economic, in this society. No one denies there are both affluent and Conservative blacks, just as there are economically disadvantaged whites (and more and more every day!). But the correlation is still strong enough to be obvious, at least to those who don't have an ideological reason to overlook it.