Congress usually maintains the status quo regarding legislation because

The legislature in turn may or may not be restricted in its ability to amend the budget. If the budget law is not approved in time, the default state of affairs may either favor the president or not. Taken together to maintain the status quo. Therefore, it will have a stalemate in the middle of congress and the president that supposedly cannot be resolved for the reason that the executive and the legislature are independently elected. The consequence is a vulnerable presidential regime since the president and the obstruction would each have an inducement to pursue an extra constitutional determination.