Voting “NO” by either part is almost never in opposition to the good parts of a bill.. almost always it’s to the thousands of other pages attached to each bill that usually specify money allocations to new government jobs that either they themselves or someone they know benefit from or the fact that it’s usually submitted less than hours before it’s set to be voted on because they know there’s not nearly enough time to wade through the hills it of each bill. Both parties do these things in a way that when they get shot down they can grandstand about their moral superiority and point fingers at the other side and say “hey I tried to fix this, but THEY prevented us… THEY are the problem” further sewing divide in an already contentious two party system

And of course sometimes it’s purely spiteful