-more difficult to control debate on senate floor
-amendments can be germane or nongermane
-if the bill is popular and everyone believes it will pass, other bills that are stuck in commity are offered as amendments to the popular bill to get them passed (they slide through with little debate; they may not otherwise have passed
OR
-a senator may offer an amendment to a bill that will "kill the bill", a "wrecking amendment", or a poison pill (no one will vote for it because of the amendment)