Henry Neufeld has an excellent post on the subject:
In my view bipartisanship means honestly listening to one another, and cooperating across party lines wherever that will work. There are two things to avoid: 1) Bickering, grandstanding, and other such tactics and 2) Compromising away your principles. I think both of these things should be avoided diligently and equally.Read the whole thing.
When two politicians disagree on a substantive issue of principle, debate it out openly and honestly, and then end up voting against one another, I regard that as good civic responsibility. When the same politicians waffle around until they find some mushy compromise, I call that dishonesty and cowardice.