It is when both parties work together to pass something. In an age of bitter division it can sound almost quaint, but the system was built to require exactly this kind of cooperation.
Bipartisanship is cooperation between the two major political parties to agree on or pass legislation. A bipartisan bill is one that draws support from both sides rather than passing on the strength of a single party.
The American system is built to need it. With separated powers, two chambers, the filibuster, and the veto, major legislation usually cannot pass on one party's votes alone. The structure pushes toward compromise, or toward gridlock when compromise fails.
It was more common in earlier eras, when the parties were less ideologically sorted and contained a wider mix of views. Landmark laws like the Civil Rights Act of 1964 passed with significant support from both parties, an outcome harder to imagine in a more polarized age.
Its decline is a defining feature of modern politics. As the parties have grown more uniform and more hostile, bipartisan cooperation has become rarer, and reaching across the aisle can even draw punishment from a politician's own side.
