What is the main topic of the talk?

We know then that in the U. S. , it’s the job of Congress to review and propose new laws, which we call bills, and perhaps to modify these bills and then vote on them. But even if the bill passed in Congress, it still doesn’t become law until the president had a chance to review it too. And if it’s not to the president’s liking, the bill can be vetoed or killed in either of two ways. One is by a veto message. The president has ten days to veto the bill by returning it to Congress, (18)along with the message explaining why it’s being rejected. This keeps the bill from becoming a law unless overwhelming majorities of both houses of Congress vote to over-ride the president’s veto. Something they rarely do. (19) Often, lawmakers simply revised the vetoed bill and passed it again. This time, in a form the president is less likely to object to, and thus less likely to want to veto. The other way the president can kill a bill is by pocket veto. Here’s what happens. If the president doesn’t sign the bill within ten days, and Congress adjourn during that time, then the bill will not become law. Notice that it is only at the end of an entire session of Congress that the pocket veto can be used, not just whenever Congress takes the shorter break, say, for a summer vacation, after a pocket veto, that a particular bill is dead. (20)If the lawmakers raise the matter in their next session, they’ll have to start all over with a brand new version of the bill.