I'm not a fan of the idea of partisanship. Partisanship tells us that those involved are representing the interests of a specific group of people rather than the bests interests of the electorate they are supposed to be representing. The point of running to be an elected officeholder is to represent the best interests of the people in the region or district that is electing you.
I dislike the idea of bi-partisanship even more. It goes further to say that you are negotiating based on the specific group's platform instead of your electorate but you recognize only a specific other party as legitimate. This completely undermines the purpose of the people of each district, state or country having a voice that represents specifically them and whomever they send to office will only be recognized or cooperated with if they are a member of one of two parties. The people of a particular electorate no longer have a unique voice for them but now are essentially forced into participating in a pre-determined voting block that may or may not represent that particular electorate's issues and needs.
Party politics undermines the American election system using democratic methods of participating in the republican form of government. Simply put, it is "gaming the system". It assembles people into general voting blocs that address many issues regardless of the need or importance of local relevance.
It's an abuse of the democratic process which leads to "mob rule" or domination of minorities by simple majorities. The U.S. founding documents are founded on the ultimate minority, the individual. Allowing "mob rules" or simple majorities to infringe upon the rights of any individual is an affront to the concept of individual natural rights.