The problem with the American electoral system lies in how Congressional districts are drawn every 10 years with the census. Increasingly, lines are drawn to ensure a victory for one party or another. Thus, districts are increasingly liberal or increasingly conservative when a victory is guaranteed. When these leaders get to Congress, divisiveness grows as liberals lean too far to the left and conservatives lean too far to the right. In the end, legislative bodies are a mess that no one seems willing to clean up.
A lot of work done by the Democrats and the Republicans is simply to the tune of discrediting each other or selfishly trying to ruin compromises or solutions to important problems. In addition to that, they are often the same brand. Their main focus is taking money from lobbyists and other sponsors, rather than truly being what they say.