How should a two-party political system work?

[Meursault]

A lot of people who in good faith complain about the dysfunctionality of the current American political scene seem to hearken back to bygone eras to show that the current cutthroat process hasn't always dominated our political life.

The 1950s in particular are often invoked as a period of collegial, rather than adversarial, two-party governance. And I'd agree with it to a point - while suggesting it is impossible to return to bipartisan consensus building ala the Eisenhower Administration.

I suggest this irreplicability is because of a shift in the structural behavior of the Parties. What Eisenhower did, for instance, was to 'conservatize' the New Deal. Decoupling interventionist economic philosophy from its left-ish moorings, he turned it instead to conservative pursuits - justifying the largest Federal public works project in history (the Interstate Highways) through the nationalist rationale of public works.

[Meursault]

After Nietzsche, I call this a 'values inversion', when the logical structure of one mode of thought is used to support concrete actions that more properly belong to another.

I don't believe this sort of maneuver is possible, on a meaningful scale, so long as the Parties separate themselves out ideologically. Am I wrong here?