In the beginning, there were The Federalists. The group included the likes of Alexander Hamilton and John Adams, and comprised mostly Northern states and were concerned with commerce. With Hamilton pushing for more federal power, Thomas Jefferson, James Madison, and the like formed the Democratic Republicans, predominantly Southern, and pushing for more power at the state level.
This bifurcation has remained with us, and while it incorporates both advantages and disadvantages, the public doesn’t show much interest in moving away from it. Carte blanche would be too much of a free-for-all. How could a winning party be selected then, when all of us, really, want things that are somewhat or majorly different from most everyone else?